Saint Isaac's Cathedral
If compared to the biggest domes realised in Orthodoxy, Saint Sava surpasses by large the Cathedral of Christ the Saviour in Moscow, whose dome has 29,8 m (outer) and 25 m (inner) diameters, the Kronstadt Naval Cathedral with 29,8 m (outer) and 26,7 m (inner) diameters and the Saint Isaac's Cathedral in Saint Petersburg with 25,8 m (outer) and 21,8 m (inner) diameters.