Kerid Crater

Kerid is about three thousand years old, roughly two hundred and seventy metres across and fifty-five deep, and its walls are a strong red because the scoria is rich in iron - unusual against Iceland's normal black. The lake at the bottom is not rainwater but the groundwater table showing through, so its level rises and falls with the water table and its colour reads opaque turquoise. It was long thought to be a collapsed cone rather than an explosion crater. The site is on private land and the owners began charging a small fee in 2013 after erosion from visitor numbers damaged the rim - a decision that was controversial in a country used to free access, and which funds the path and steps.

What you actually see

• Red scoria walls - iron-rich rock, against Iceland's usual black.
• A groundwater lake - the water table showing, not rain collected.
• A rim path and steps down - built and maintained from the entry fee.
• A charged site in a free-access country - the 2013 decision and its context.

When to go

May to September. An hour.

Honest expectations

It is small and takes half an hour - a stop on the Golden Circle, not a destination. It charges, which surprises people. Coaches arrive in waves. The steps down are steep and icy in shoulder season.

Nearby

Faxi and the Golden Circle sites are north; Selfoss is south-west.