overview opening hours admission The 6-floor building of the former waterworks overlooks the Letná plain. The tower, which is in total 38.3m in height, is crowned with a pyramidal roof. The top part of the tower features a column extension with a tower-clock. On the fifth floor there is a view gallery and a periscope which monitors some of the Prague’s monument. A Foucault pendulum has been installed in the foyer of the main staircase. opening hours january—december mon closed tue 14:00—18:00 wed closed thu 14:00—18:00 fri closed sat, sun 14:00—18:00 more about opening hours admission basic 75 CZK reduced 50 CZK more about admission Source: Vodárenská věž na Letné admission basic 75 CZK reduced 50 CZK opening hours january—december mon closed tue 14:00—18:00 wed closed thu 14:00—18:00 fri closed sat, sun 14:00—18:00