Near the entrance to the Sea Garden is the Astronomic Observatory and Planetarium "Nikolay Kopernic". Built in 1962 in connection with the 8th International Congress of Astronomy it is unique on the Balkan Peninsula. The diameter of the planetarium cupola is 10/5 m and 5 500 stars can be projected on it. The pendulum of Foucault, which proves that the Earth turns around its axis, is mounted in the tower.