Kaali Meteorite Crater

Somewhere around three and a half thousand years ago an iron meteorite broke apart over Saaremaa and the main fragment hit the ground at Kaali. The impact left a crater roughly 110 metres across with a raised rim, and eight smaller craters scattered around it. It is one of the few impact events in Europe that happened after the area was inhabited, which is why it turns up in local folklore.

What you actually see

A near-perfect circle of dark green water sitting in a bowl, with a rim of broken limestone pushed up around it and trees growing over the whole thing. From the rim path you get the shape clearly; from the water's edge it just looks like a small pond, so the walk around the top is the point.

The satellite craters in the surrounding fields are shallower and easier to miss - some are marked, and a couple are little more than damp hollows.

When to go

• May to September - the pool holds water and the rim path is dry.
• Autumn - the trees around the rim turn, which sharpens the circle.
• Winter - the pool freezes and the shape is still readable under snow, but the visitor centre may be seasonal.

Honest expectations

It is small. Photographs taken from the air make it look far more dramatic than the view from the rim, where trees break up the outline. Give it an hour and the walk around the top, and it holds up; arrive expecting Arizona and it will not.

The water level in the pool varies a lot with the season, and in a dry summer it can drop to a muddy patch.

Nearby

Kuressaare and its castle are twenty minutes south. The Angla windmills are a similar distance north, and the two make a natural half-day loop.