There is a bridge crossing the lake, and from the bridge you can get to a small island where the fort is. On the bridge there is a road with no space on the side and cars going fast, as well as a railway. The best to get to the island is to walk down the bridge near the water, until reaching the island, and then carefully cross the road and the railway.
It's a cool place to camp. In august 2014 ten hitchhikers stayed there a couple of days. There is no roof to sleep under, but plenty of space for tents, and you are not visible from outside. Once every two days a tourist might pass by.
Also be careful of snakes in the water and in the rocks near the shore. Vipers live there.