• Sun viewing by day on weekends, holidays and in summer, when daytime hours open up for filtered telescope views of sunspots
• Evening sky sessions for the moon and planets are the core program, and opening times shift with the season, so check before going
• Petřín Tower and Mirror Maze are a short walk away in the same park, and a combi ticket covers all three

A public astronomy observatory from 1928 on Petřín hill, built against the medieval Hunger Wall. Its three domes hold telescopes, including a historic Zeiss double astrograph in the main dome. On clear days visitors look at the sun and sunspots; after dark, the moon, planets and deep-sky objects. Inside there is a permanent astronomy exhibition, and the Astrobistro café sits on the ground floor.