The  dual fortification system protecting Visegrád was built by Béla IV after the Mongolian invasion, around 1250-1260. The monumental residential tower of the Lower Castle, the so-called Solomon Tower is a 34 meters tall building with a hexagonal plan. On the first floor of the five-storey building was the toll-collector's place, the others floors had residential rooms and there was a rampart walk on the top.

The building was named after Solomon by a mistake but it is already stuck in public knowledge. King Solomon was a prisoner in Visegrád but he was not kept in the Lower Castle as the fort system was not even built yet at the time.