The great dome of the Basilica of the Sacré-Cœur (Sacred Heart) of Montmartre rises to a height of 83 metres. It is the second highest point in the capital after the Eiffel Tower, its republican counterpart, completed in 1889 for the World Fair. Topped by a roof light in the form of a colonnade, the great dome encloses a central cupola 54.94 metres high under the keystone and 16 metres in diameter. Its interior and exterior galleries are accessible, after the security check, at the level of the moat on the left side of the basilica by a spiral staircase of some 300 steps.