The Sirente crater field of more than 20 extremely well preserved structures was discovered during the late 1990s and was originally though to be due to a very recent meteoritic impact (about 1500 years ago).
However, further investigations now points to it being a water reservoir for human pastoral activity. Another plausible alternative is that it is periglacial feature (i.e. Pingo).
The largest crater, filled with water, has a maximum rim-to-rim diameter of 140 meter.
A prominent ridge encircles the lake.
No meteoritic fragments have ever been found.