| | Public
Stjerneborg or "Star Castle" was Tycho Brahe's 2nd observatory next to his palace-observatory Uraniborg. He built it because Uraniborg was too unstable to do good readings of the stars.
It got destroyed after Tycho Brahe's death.
The underground portions of the observatory were excavated in the 1950s and are today fitted with a roof approximating the original one. The chambers now house a multimedia show open to the public.