The Powder Tower - Prasna brana - is situated next Prague Municipal House, The Powder Tower served as an entrance to the Old Town since the 11th century. The name Powder Tower originated in the 17th century when the tower was a gun powder storage place. Prasna brana in Czech or Powder Tower in English used to be part of Old Town fortification system. The main part was built by Matej Rejsek in 1475. In the 18th century it served as a gun powder depot, giving the name to the tower. The Tower observation gallery is 43 metres above the ground and offers a beautifull view of the historiacal town.