The chapel of the 18th century Catherine's Palace of Tsarskoye Selo. The palace is located just outside St. Petersburg, Russia and a wonderful site to visit.
The chapel was designed by architect Chevakinski for empress Elizabeth I.
In the tradition of the Orthodox Church the central dome represents Christ, the four smaller domes the Gospel Evangelists.
The palace itself (the lower part of the photo shows a tiny fraction of it) is designed by Rastrelli.