St. George's Church known also as Oplenac Church and Oplenac Mausoleum, is the Mausoleum of the Serbian and Yugoslav Royal House of Karađorđević located on top of the Hill Oplenac in city Topola, Serbia.

The entire mosaic has 725 painted compositions (513 in the temple and 212 in the crypt), on which there are 1500 figures. The entire area of the mosaic is 3,500 square metres (38,000 sq ft); with 40 million various coloured pieces of glass which have 15 thousand different varieties of colour, making the most vivid artistic impression.