Adventure in Yokohama Citizen Forest: War On Bold Mountain: Tsukuiko Shiroyama Park 津久井湖城山公園

When we google Earth, West Kanagawa is covered with green. On the border between the grey cities and green forest, the City of Sagamihara 相模原市 situates itself. Geologically speaking, the city can be divided in 2 areas both of which were created by Sagami River 相模川. One is Sagamihara Plateau where the downtown Sagamihara is spreading and creates a grey concreted area in Google Earth. Another is river terraces, where Sagami River runs in the middle of greenery. Actually the latter area is a gateway to climb the main ridge of Tanzawa Mountains 丹沢山系, and as such it’s very mountainous area. For millennia, the area has been the main route connecting mountainous middle Japan (I mean, Yamanashi, Nagano, and Gifu prefectures) and Kanto region. During the medieval period, a powerful warlord of Yamanashi, Takeda clan 武田氏, and another big chieftain of Odawara 小田原, Hojo clan 北条氏 who governed the entire Kanto region, faced-off each other in mountainous east Sagamihara, and so the present day border between Kanagawa and Yamanashi was determined. The largest fortress for Hojo family was strategically located on the border between the diluvial plateau and the river terrace of Sagami River. The place once-called Tsukui Castle 津久井城 is now Tsukuiko Shiroyama Parkof Kanagawa Prefecture 神奈川県立津久井城山公園. This week, I report you my adventure in Shiroyama hill 城山 with well-maintained trekking roads where parents can bring their venturesome kids to try their hiking skills. As remains of medieval fortress, it’s the biggest in Kanto region. I experienced how tough those samurais were in Shiroyama. They fought tooth and nail to defend their territory in such a steep mountain slopes. Amazing.

Shiroyama fortress, which is now a deep forest.

If you come to Tsukuiko Shiroyama Park outside of Kanagawa Prefecture, the easiest way is via Kenoh-do Express Way 圏央道 by car and exit from Sagamihara IC to reach to Tsukui Lake 津久井湖. (More to this lake in my later post: it has a deep connection with Yokohama.) Go to Shiroyama Dam 城山ダム, and beyond the dam, there is Tsukui-kanko Center 津久井観光センター, a tourism center of Tsukuiko Shiroyama Park that has an ample free-parking space. When you use public transportation, first go to Hashimoto Station 橋本駅 of JR Yokohama Line, JR Sagami Line, and Keio Sagamihara Line. Leave the station from the North Exit to take Kanachu bus service Hashi-01 橋01 (time table, here) to Mikage 三ヶ木 at bus stop #1 or #2. It’s about 30min ride to Tsukui-kanko Center Mae Stop (i.e. in front of the parking space) or its next, Kita-Negoya Stop 北根小屋. Those are the bus stops to hike Shiroyama forests. Around Shiroyama Dam is one of the best spots for cherry-blossom BBQ party in the area, and due to its proximity to the population center of west Tokyo, the place could be uber-congested in March-April. If you plan to go there in early spring, better to have a good planning.

The tourism center of Tsukuiko Shiroyama Park.
They daily sell local sweets, and fresh produce.

It’s a bit tricky to find #1 and 2 bus stops
in the north exit of Hashimoto Station.
When you exit from the ticket gate,
turn left and go to the open space
constructed above the bus-terminal.
Once you find the sign of this photo,
simply follow the arrows leading us to #1-3 stops.

77.7ha park on the western edge of Tsukui Lake is consisted of 2 flower gardens next to the dam (and the parking), Hana-no-enchi 花の苑地 and Mizu-no-enchi 水の苑地, a forest hill, i.e. the Shiroyama fortress, and an outdoor archeological museum called Negoya 根小屋 area where the ancient samurais for the fortress lived with their family. (2pp map of the park is here and here.) For you who are interested in Japanese history and archeology, the booklet here (in Japanese) explains the story of the place. According to this document, the place had a substantial expansion till April 1590 when the samurais of Hojo Clan protected the place surrendered to the army of Tokugawa Ieyasu 徳川家康. The museum is explaining medieval way of life of samurais. I think the nearest access to the museum is from Kitanegoya Bus Stop. From the bus stop, go back a bit to the traffic right and enter the community road going to the direction of the hill. The road meets with T-crossing and we turn left here. The third corner after turning left shows small shrine (Koami Suwa Shrine 小網諏訪神社) and steps ahead on the left showing the way to enter the hill. At the end of the steps next to the shrine, there is a bio-tech toilet with a nice view of Tsukui Lake, and a paved pedestrian road that connects the tourism center on the shore of the lake and the museum behind the hill. Turn right here and a 10min-or-so walk will bring you to the archeological site.

Shiroyama hill seen from Kitanegoya

Could you figure out the steps over there?
By the way, the community along the lake was built
in the 1960s by the people who moved
from the ancient communities along Sagami River.
They had to move due to Shiroyama Dam, operational since 1965.
So, the shrine next to the steps was moved
from the original place now in the bottom of Tsukui Lake.

The paved road to the museum.
A structure on the right along the road is …

A bio-tech toilet.
Your droppings will be processed by microbes
living underneath the toilet seats.
No water flushing is necessary
(; you must use the toilet paper provided there.)

The Shiroyama Hill itself is now remains of medieval fortress covered with a well-established forest. The trekking roads within Shiroyama have 4 viewing spots, 3 to the north and 1 to the south. This was the frontline for medieval wars, and the view from the fortress is located damned reasonably. The viewing spot to the south (in the map, the location with No.6) is at the entrance of museum coming from the bio-tech toilet where visitors can observe the entire village nestled in the beginning of Tanzawa Mountains. Beyond the samurai village was a fierce battle ground in 1568 with 40,000 soldiers of Takeda and Hojo Clans. The view along the road running near the toilet (No.4) is observing Tsukui Lake, along which runs National Route 412 connecting to Route 20 near JR Sagamiko Station 相模湖駅. From here, sentinels could spot the army of Takeda clan coming from the west. Another two (No.11 and 12) locate in the east of the Park looking down the megalopolis Tokyo. So, when the army of Tokugawa came from Tokyo (Edo), this was the spot for the watchmen of Hojo to find out. Actually, from No. 12 point, on a fine winter day, it’s possible to figure out beyond the trees Tokyo Skytree to the north. The current trekking roads in Shiroyama are remains of roads of the fortress connecting these viewing spots with the last stand of the lord of the castle at the peak (375m ASL). Naturally, they are ringed roads strategically connected by spokes.

A view from the toilet. Nice, isn’t it?

Unfortunately, when I’ve been there,
it was a short window of rainy summer days of 2017.
This was the best shot I could take
for a view from Shiroyama No. 12 to Tokyo.

Roughly speaking, the fortress has 3 ringed roads circling the peak which was the last bastion for the Lord of Tsukui Castle. The design of the routes is following the standard war strategy. The north side of the ringed road around the foot of the fortress contains the steepest and sometimes trickiest feature of the road within the park, including fragile ridges and long and rocky slope equipped with chains for the climbers. The entrance to the bastion was made difficult. (In the map, it is from Point No.1 è No.4 è No.60.è No.7èNo.8èNo.11èNo.12èNo.13èNo.2è No.1.) The second inner ring-road running through Point 18 and Point 15 is a utility road that does not require difficulty for the hikers who have managed the outer circle road of the fortress. The inner-most road, called Honjo Kuruwa 本城曲輪 (meaning, “the corridor of the last stand”), is more of a hallway within the castle around the peak. We can stroll Honjo Kuruwa in woods just like wandering in an urban park. Honjo Kuruwa has still ongoing archeological excavation so that please keep off from the cordoned-off places. These 3 ringed roads are connected by steep slopes all of which let us recall this is the place of war so that the approach to the peak cannot be easy.

The trekking route between points #2 and 13
equipped with chains to support hikers.

Though steep,
Kanagawa Prefecture maintains the roads well.

Viewing Tsukui Lake from Honjo Kuruwa

The archeological study is going on
at the peak of Tsukui Shiroyama.

There is a toilet at the peak.

In Honjo Kuruwa, they situated many boards
explaining the history and design of the castle (in Japanese).
The place is like an open-air museum.

By the way, #18 sign post of the second inner circle of Shiroyama is a photo point for Kanto Fureai-no-michi (Metropolitan Nature Trekking Route 関東ふれあいの道). It’s a sort of programme orchestrated by the Ministry of Environment of Japan to encourage metropolitan dwellers to experience nature surrounding the Kanto region. Kanagawa has 17 routes for the scheme (the detail is here), and you collect your photo taken at the designated points, send them to Kanagawa Natural Environment Conservation Center, and they will give you a certificate of “conquering all the routes in Kanagawa” and a budge. (The address of the Center will be at the end of this post.) If you do the same for all the 7 prefectures in Kanto region, you send your photos of the last prefecture together with the certificates of the other prefectures. Then, you’ll receive a grand certificate and a special budge of your achievement. It’s a project of walking 160 courses of roughly 1800km … "Why did you want to climb Mount Everest?" "Because it's there." George Mallory.

Inside of the fortress,
the sign posts are located in a strategic point
so that in case you lose your route,
you can simply return to the sign post
to figure out your intended direction.
To report your achievement to the Conservation Center,
you take your photo with these signs.

There are only 3 openings to the second inner circle road from the outer ringed road. The easiest is from the museum area to No. 15. The road is steep but the widest and there remains a little bit of the stone-pavement. A part of second ring-road from the museum area is called “Kuruma-zaka 車坂,” i.e., Car Slope. It was possible for 2 cavalries to proceed on this route side by side. The staff of the fortress must have commuted to their office daily, sometimes with supplies loaded on a cart. The other 2 roads are trickier. One from the northwest of Koami Suwa Shrine, and another from the southeast No.13 point, both of which are very steep. At point No. 13 (approx. 350m ASL) there is a pond named Takaraga-ike 宝ヶ池, aka Treasure Pond, which is said to be never dried-up. Also, the water of the pond is always cloudy so that people believe when samurais were busy in Tsukui Castle, they must have washed tons of (sometimes bloody) Japanese swords there. I don’t know the legend was true, but the pond is surely the evidence that Tsukui Castle had maintained an abundant supply of water even under emergency. Next to the pond there is a small shrine, Iizuna Shrine 飯縄神社, that is a home of Iizuna-gongen who is an apparition of Acala presiding, needless to say, war. Iizuna-gongen’s main home is Takaosan (Mt. Takao) situated northeast of Shiroyama. Mt. Takao was also the territory of warlord Hojoh who treated anything connected with Iizuna-gongen well. It’s no wonder they donated another home for this deity within one of the most important fortresses in their territory. The road system around the shrine, called Iizuna Kuruwa 飯縄曲輪, is precipitous and contains lots of remains of dry mort and sentinel points including fire beacon platform site. Unless we pass this point we cannot enter the second inner circle road from the east.

Kuruma-zaka to point #15

At #4 there is this box for hikers to pick up a map of the fortress.
It’s the same map downloadable from the sites I cited above.
This is very useful info.

A way from #4 to #18 is
steep and winding trekking road.

Takaraga-ike

Iizuna Shrine

The view to Mt. Takao from the top of Shiroyama.
Takao is not that far from here.

From the second inner circle road to enter the Honjo Kuruwa corridor of the last stand, there is only one road. It starts from Point No.15. In the middle between No. 15 and the peak, there is a relatively flat space called Taiko Kuruwa 太鼓曲輪, which is considered to be the remains of a house for the second commander of the castle. After this pace, we face a small but very sharp valley called Horikiri 堀切 that was artificially created by digging the ridge to defend the last bastion. Now it’s just a short and steep going down and up, but before the place was almost a cliff and the samurais threw there a wooden rudimentary bridge named Hikihashi 引橋 that could be easily removed when enemies approached. At the end of climbing Horikiri, there is a large stone monument erected in the early 19^th century by Shimazaki Tadanao 島崎律直, the village chief of the current museum area. He was a descendant of one of the followers of the defeated Lord of Tsukui Castle, Naitoh family 内藤氏, and paid cool 50 thousand Ryo in 1812, equal to USD 25 million now. It was a commemoration of the killed souls some 220 years ago then … Really, people remember such things for a very long long long time …

Point #15

Taiko Kuruwa.
Taiko means drums, and, for this case, war drums.
Academics are debating
the meaning of the name Taiko Kuruwa here.
I think it is natural for the second commander
to be in charge of war drum.
Don’t you think so?

Horikiri.
At the beginning of this place, there is …

Educational board explaining the logistics of war at that time.

Crossing Horikiri,
the slope is steep …

And there, this is a handsome 25 million dollar monument.

In Honjo Kuruwa, there is a post
inviting you to drop your own haiku or poem
depicting your impression of Tsukui Shiroyama.
Your art will be displayed in the museum of Negoya.

So, the ground of Shiroyama Hill probably absorbed lots of blood, and now the soil must be very fertile. Also, the place keeps the underground water very high. Near Takaraga-ike, 350m ASL, there is a remnant of gigantic cedar tree that was thunder-struck in 2013 and died at the age of approx. 900 years old. Cedars cannot grow that long and big unless there is enough groundwater. Naturally, the vegetation of Shiroyama Hill is rush and I found lots of mushrooms sprouting when I’ve been there during a pocket of wet summer days. Near Point No.2, they have a beautiful forest of cypresses planted some 120 years ago. The atmosphere is filled with the aroma of noble Japanese cypresses … The Park Office provides a nice free nature-guide booklet (in Japanese, downloadable from here). According to this document, Shiroyama Hill was a bald mountain when it was a fortress. Er, well, as a battle ground, of course lots of trees were simply obstruction. Samurais must have cut vegetation vigorously. Then, after conquering Tsukui Castle, Tokugawa Ieyasu grabbed the land and ordered to afforest the entire area massively in order to create a buffer zone, in case another enemy approached to Edo (Tokyo) from the northwest. Later, this defense policy was transformed to industrial policy of timber production. Now the border area between Tokyo, Yamanashi, and Kanagawa Prefectures have vast “public forest mountains” originated from the afforestation ordinance by Tokugawa Shogunate government. It’s a sort of important when we consider Yokohama’s water and forests. I return to the topic in my later posts.