Goshiki-numa

Mount Bandai's northern flank collapsed in the eruption of 1888, sending a debris avalanche across the plateau that dammed the streams and left several hundred ponds and lakes behind it. Goshiki-numa, the five-coloured ponds, is the cluster nearest the road, and the colours are real and different from one another - cobalt, emerald, turquoise, jade - because the water in each carries a different balance of iron, silica and other dissolved minerals from the debris. The same pond changes with the light and the season, so the descriptions in guides rarely match what you see. A trail of about four kilometres links them, from the Goshikinuma entrance past Bishamon-numa, the largest, where rowing boats are for hire, to Urabandai Kogen, and takes about an hour and a half at an easy pace. The plateau is thick beech and birch and colours through October.

What you'll find

• Different colours in each pond - dissolved minerals from the 1888 debris avalanche.
• The linking trail - about four kilometres from the Goshikinuma entrance to Urabandai Kogen.
• Bishamon-numa - the largest pond, with rowing boats and a view of Bandai.
• Beech and birch - forest on the debris plateau, colouring through October.

When to go

May to early November; late October for colour. Two to three hours.

Things to know

The colours are subtler than photographs suggest and flatten in dull weather. The trail is muddy after rain. Autumn weekends are congested and the car parks fill. The route is closed by snow in winter.

Nearby

Mount Bandai rises to the south; Lake Inawashiro is beyond it.

Key facts