The name of this high and bizarre rock - Hercules' Club - perfectly captures its shape.
There is of course a number of legends explaining its strange form. One of them says that it is actually a club of Krak, the legendary ruler of Krakow, who apparently used this terrible weapon to kill the Wawel Dragon.
Anyway, the rock is a really impressive geological formation, and is worthy to spend some time just to watch at it.