West Shimane · HamadaNo.808★★Open in map →
Iwami Tatamigaura
— Raised sea floor on the Hamada coast
A level shelf of old sea floor on the Shimane coast, cracked into mat-sized panels and studded with round stone nodules. You reach it through a tunnel cut behind the beach, and then walk out onto the rock itself.
- FromHamada Station
- Train + 20-25 min walkJR local train, then a walk
- Get off atShimoko Station (JR San'in Line)
- From there
- Iwami Tatamigaura
The sweet spot
This is not a hidden coast. It is a designated national natural monument, with a car park and signboards. What keeps it uncrowded is that it sits off the main San'in sightseeing line, and that the platform is only fully walkable around low water.
Where it is
14 more notes in Shimane · open the map →What to look for — in walking order
- The entrance tunnela short cut passage behind the beach that opens straight onto the rock
- Senjojikithe level platform itself, divided by joints into mat-like panels
- The nodulesrounded concretions grown around fossil cores, set in rows across the flat
- Uma-no-sea low rock ridge running through the middle of the platform
- Inujima and Nekojimatwo sea stacks standing in the water beyond the platform edge
How to actually get there
- Hamada Station to Shimoko Station (JR San'in Line, local train).
- Shimoko Station to the Kokubu shore on foot, following the signs for Iwami Tatamigaura.
- Through the entrance tunnel and out onto the wave-cut platform.
- Across the flat past the nodules to the ridge in the middle, then back the same way.
- JR San'in Line from Hamada
- Hamada Station is the gateway for this stretch of coast. Take a local train north on the JR San'in Line to Shimoko, an unstaffed station, then walk to the shore; official guides put that walk at twenty minutes and at twenty-five. Trains on this line are widely spaced, so read the timetable before you set out.
- Return from Shimoko Station
- Walk back the way you came and take the JR San'in Line south to Hamada. Departures are thin even in the middle of the day, so photograph the timetable on the platform before you head down to the shore, and do not count on a late service.
About the place
Iwami Tatamigaura sits on the Kokubu shore at the western edge of Hamada, in Shimane. The wave-cut platform covers about 49,000 square metres of level rock, backed by a cliff of conglomerate and sandstone. Joints divide the surface into panels, and that pattern gave the place its name: mats, laid out across a shore. Scattered over the flat are nodules, rounded concretions grown around fossil cores, standing above the rock like stools. Whale bone, shells and driftwood are held as fossils in the beds themselves. Two sea stacks, Inujima and Nekojima, stand offshore beyond the edge.
How to enjoy it
Check the tide table before you go: around low water the flat is at its widest and driest, and a rising tide closes off the far end. Morning light comes in low across the joints and makes the mat pattern easy to read. Leave yourself enough time to walk out to the ridge and back without hurrying the tide.
Background & history
The rock formed on a sea floor in the middle Miocene, roughly sixteen million years ago, and then spent most of that time buried. Uplift along this coast brought the beds back to the surface, and the Hamada earthquake of 1872 raised the shore again, exposing more of the platform. Geologists took an interest early, and the site was designated a national natural monument in 1932. Because the fossils and structures lie in the open where anyone can look at them, the shore has long been described as a natural museum of geology.
Before you go
- Cash
- The shore itself has no admission charge. The car park beside the site is paid, at 200 yen per car at the time of checking. Shimoko is unstaffed, so sort out your ticket or IC card before you travel and carry some cash.
- Before you go
- The platform is uneven wet rock and is best left alone in rough seas or at high water. The Meganebashi arch is closed to foot traffic on safety grounds. There is no lighting on the shore, so treat this as a daylight visit.
- Another way
- From Hamada Station you can also take a bus toward Gotsu, get off at Senjoen-guchi and walk down to the coast from there.
- After you get off
- From Shimoko Station, head north-west toward the Kokubu shore and follow the signs for Iwami Tatamigaura. The tunnel entrance is at the back of the beach, and the platform opens out on the far side.