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Niemonjima

— Chiba's largest island, reached by hand-rowed boat

historyOff the trail — and worth it

A small island just off Futomi in Kamogawa, home to a single family and listed as a Chiba Prefecture Place of Scenic Beauty. A hand-rowed ferry makes the crossing, and a loop path links a legendary cave, poem stones and an old island house.

FromTokyo Stn
2 hr+ (with a transfer)JR express + local line
Get off atFutomi Stn (JR Uchibo Line)
From there
Niemonjima

Directions ↗

The sweet spot

This is a well-known Kamogawa sight and a listed scenic spot, so it is not a hidden place. What makes it different is the access: with no bridge, every visit begins with a short crossing in a hand-rowed boat.

Where it is

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What to look for — in walking order

The hand-rowed ferrya small boat rowed by hand from the Futomi landing to the island entrance
Poem-stone patha hillside path lined with stones carved with verses on the island's seasons
Hojima Benzaiten shrinea small shrine to the goddess Benzaiten along the hill path
The Hirano residencethe island family's house, over 300 years old and partly open to view, with a large cycad in the garden
Kagura-iwa and Yoritomo's cavethe east-side rocks linked to Nichiren, and the legend cave that now holds a small Inari shrine

How to actually get there

Tokyo Stn → Awa-Kamogawa Stn (Limited Express Wakashio, about 110 min).
Awa-Kamogawa Stn → Futomi Stn (JR Uchibo Line local, 1 stop; reduced service after Typhoon No. 25 as of Oct 2026).
Futomi Stn → ferry landing at Futomi fishing harbour (walk ~12 min).
Landing → Niemonjima (hand-rowed ferry, included in admission).

Wakashio express, then one stop on the Uchibo Line: Tokyo Stn →(Limited Express Wakashio via the Sotobo Line, about 110 min)→ Awa-Kamogawa Stn →(JR Uchibo Line local, 1 stop)→ Futomi Stn →(walk ~12 min)→ the ferry landing. As of 1 Oct 2026, JR East reports Uchibo Line trains between Kisarazu and Awa-Kamogawa running at about half the usual frequency after Typhoon No. 25, so check the connection at Awa-Kamogawa before you set out.
Return via Awa-Kamogawa: Walk back to Futomi Stn, ride the Uchibo Line one stop to Awa-Kamogawa, then take the Wakashio or a Sotobo Line train toward Chiba and Tokyo. With the Uchibo Line on a reduced timetable, note the return times when you arrive at Futomi.

Directions from my location (Google Maps) ↗

About the place

Niemonjima sits just off the fishing harbour at Futomi, on the Pacific coast of southern Boso. At about 30,000 square metres, it is the largest island in Chiba Prefecture. It is privately owned. One family, the Hiranos, lives there, and the island is named after Hirano Niemon, its first lord. There is no bridge. A boatman rows visitors across from a landing in the harbour. On the island, a single path climbs past poem stones and a small Benzaiten shrine to the family residence, then drops to the rocks on the east side and back to the shore.

How to enjoy it

Allow about 30 minutes to walk the loop, and longer if you linger at the house or on the eastern rocks. The ferry runs as needed during opening hours. The rocky shore is also used for rock-pooling, and summer brings swimmers.

Background & history

Local tradition says that in 1180, after losing the Battle of Ishibashiyama, Minamoto no Yoritomo, later the founder of the Kamakura shogunate, fled to Awa Province, and Niemon hid him on this island. The family is said to have received the Hirano surname and local fishing rights in return. A cave on the east side is still called Yoritomo's hiding hole. Another legend says the monk Nichiren worshipped the rising sun from Kagura-iwa rock. The family house was lost to the Genroku earthquake of 1703 and rebuilt in 1704.

Before you go

Cash: Island admission, which includes the round-trip ferry, is listed by the operator at 1,350 yen for adults, 1,050 yen for junior-high students and 950 yen for children from age 5 through elementary school. The official site does not state payment methods, so carry cash.
Good to know: Open 9:00–16:00, but the island closes on days when the ferry cannot run in bad weather. The official site's ferry status is scheduled to update each morning. Pets cannot be brought onto the island.
Another way: From Awa-Kamogawa Stn, Nitto Kotsu's Kamogawa city-line bus runs to the Niemonjima-iriguchi stop, and taxis are available. Kamogawa City reported this line running on partial detours after Typhoon No. 25 (as of 28 Sep 2026), so check Nitto Kotsu's notices. The same line also runs to Tanjoji-iriguchi on the Kominato side.
After you get off: From Futomi Stn, walk about 12 minutes to the ferry landing at Futomi fishing harbour. If the boat is moored on the island side, the official site asks visitors to wave the flag at the landing.