Tunguska event
Lake Cheko is a small freshwater lake, about  from the center of the event. The lake does not show on maps of the area which are older than about 1928. Before 1908, it seems to be unknown. The lake is shaped roughly like a rectangle; it is 708 metres long, 364 m wide, and about 50 m deep. In 1999, Luca Gasperini did a study on the sediments in the lake, and found that the lake predates the event of 1908. In 2007, National Geographic cites him as he states that it is possible the lake formed as an impact crater.This is argued upon due to the spread of trees, that were destroyed from the mostly agreed upon meteorite explosion.