Stjerneborg was Tycho Brahe's underground observatory next to his palace-observatory Uraniborg.

drawing of an above ground view of Stjerneborg

schematic of Stjerneborg showing underground chambers

Tycho Brahe built it circa 1581 when he found Uraniborg neither stable nor large enough for his precision instruments. He named it Stellaburgi in Latin, meaning castle of the stars.

The underground portions of the observatory have survived and are today fitted with a roof approximating the original one and the chambers are open to the public.

Click on the schematic for more details on the function of the various chambers.