Rocktogon in Budapest is a Rock Club in Mozsár utca near Oktogon. That’s actually where the name Rocktogon comes from. I have never been in Rocktogon but as I heart it is a nice Rock Club with mixed guitar music and good athmosphere. From the outside the entrance is a little bit hidden and small as I checked when I passed the club once.
With the adress it should not be a problem to find Rocktogon.