Both sinkholes were created by the collapse of underground voids created by the dissolution of gypsum deposits by groundwater.
The Southern sinkhole exceeds 300m in diameter, but is visually less impressive.
The slopes of this sinkhole are less steep and covered with sparse vegetation.
There is a small, light blue lake on the bottom of sinkhole.
The water level and the size of the lake is changing.
Panorama of the two sinkholes.Photo credit
Sources:Wikipedia/Wondermodo
