They look like real craters. However, this is not the case. These places were formed as a result of the flow of lava and hit it in the water bodies such as lakes, marshes, and the moisture evaporates explosively.
The most prominent areas to psevdokraterov is the northern part of Iceland. It was formed about 2300 years ago, when there flowed streams of basalt lava. The lava was spreading along the valley until you fell into the Arctic Ocean, flowing down from a low altitude. The valley was a big lake, the waters of which came spreadable lava. From getting into a lot of water, the lava exploded arrays and the cooling lava fell on the surrounding landscape, forming a small crater. Given the fact that the area was characterized by swamps and marshes, depressions become even greater.