In the center of the Palace square is the column of Sigismund is Poland's first secular monument erected in 1644 by king władysław IV to his father Sigismund III Vase.

The entire Eastern part of the square is the Royal castle. In the XIII century there was a wooden fortress, then built a Palace, around which eventually grew Old town. After the transfer of the capital from Krakow to Warsaw in 1596, the castle became the official Royal residence. During the next reconstruction of the castle appeared pentagonal layout with three gates. On the square facing West Gentry gate is topped with a 16-metre high clock tower.