This picture is from the JPL photo files. Others can find the original as well. This photo shows what appears to be a moderate sized lake. The lake has a definite lake edge. It does not seem to have sand, as we would on earth. The land mass just stops at the edge of the lake.
The lake also is transparent and has a deeper section within it and one can see the bottom as it drops down and the side of the deepening then are shown.
Perhaps what is more curious about this one picture is that there are darker spots around the lake,m suggesting that something is growing. By something it could be living or it could be crystalline in nature. It there is a growth pattern observed. But as said, not necessarily alive.
Notice that on the left of the picture, possibly on the downside of the picture we have the darker patches and the patches spread out in a pattern. That pattern could mean growth in the cellular sense or it could mean growth in a crystalline or mineral sense.
On the left it even appears that there might be an over-spill, into the growth area on the far left.