What you see on the picture is not a crack in the rock, it is the road to a small village in Western Rhodope Mountains not far from the Bulgarian-Greek border.
It is scary to look at it during the summer. I do not want to imagine what it is like to drive there during the winter season. Especially having in mind that the road is covered with holes. The good news is that they are reparing it now.
Just a hint, if you are going to Yagodina's Cave you might be stopped by the so called Border police (Granichna politsia) and asked for Id. So better have it with you, otherwise you might be fined.
Vacha Dam is situated in south Bulgaria, Rhodopes Mountains, Devin municipality. It is located near to road from Krichim to Devin. Altitude 680 m above sea level.
In the past it was called Antonivanovtsi Dam, named after a group of communist activists :) After the fall of the communist regime, in 1999 it gained its new name.
I was told that the place is good for fishing.
15 meters from “Vacha” Dam is Atanas Spiridonov chalet.