Awamata Falls

Chiba's geography does a lot of the work at Awamata Falls — the rest is knowing when to show up.

Awamata is a broad shallow fall about thirty metres high on the upper Yoro river, and it is unlike most Japanese waterfalls in that the water slides down a wide rock apron rather than dropping — the whole face is a sheet of moving water across a sandstone slab, which is why it is sometimes called the sliding falls. You can walk right down to the pool.

It is the centrepiece of the Yoro valley, the main gorge system of the Boso peninsula, and the reason people from Tokyo drive an hour and a half in late November. Chiba is the last place in Honshu to turn — the autumn colour here peaks around the very end of November and into early December, weeks after everywhere else — which makes the Yoro valley the final stop of the season for people who want one more go at it. A trail links a string of smaller falls along the river.

The sliding, sheet-like character of the falls comes down to the local geology as much as the river's volume — the Boso peninsula's sandstone and mudstone layers erode unevenly, and where a resistant band of rock sits close to the surface the river tends to spread out and slide across it rather than cutting a narrow notch and dropping straight down, which is why several of the peninsula's better-known waterfalls share this same wide, gentle profile rather than the tall vertical drops more associated with waterfalls in Japan's mountainous interior. That gentler shape is also what makes it safe and inviting to walk right up to the base, something that would be reckless at a narrow plunge pool fed by a genuine freefall. The valley's late foliage season is itself a product of the peninsula's mild, ocean-moderated winters — the same coastal warmth that lets citrus and other subtropical plants grow further north here than almost anywhere else in Honshu also delays the cold snaps that trigger leaf colour elsewhere, leaving Yoro's gorge as one of the last places in the country still turning while most of Japan has already gone bare for the season.