The French windows

The presence on the upper floor of stone supports and of three French windows overlooking the octagonal courtyard, without railings or balustrades, suggests the existence of a cornice of the windowsill or of a hanging gallery that ran along the courtyard. This hypothesis would seem to be confirmed by stone supports still visible in the masonry, demonstrating the high level of engineering deployed at Castel del Monte.

The French door in this room has an external façade, framed by a rectangular frame, in coral breccia, and includes two thick lintel jambs, surmounted by a round arch with an oculus in the center. Two slender columns with Corinthian capitals rest on the structure, which support a fake lintel beam with a vegetal festoon. Due to the elegance of the framework and the refinement of the carving, the French windows of Castel del Monte anticipate the aesthetics of Renaissance architecture.

The room is connected to the nearby octagonal tower, called "of the Falconer", equipped with a spiral staircase to reach the ground floor and terrace.