The Archaeological Department of India has undertaken the preservation of the great dome of the Gol Gumbad at Bijapur. The work being of great technical interest to archaeologists and engineers, is described in this article in some detail. The mausoleum, which covers an area of 18,110 sq. ft. without an intermediate support, has the biggest dome roof in the world. The monument was built between 1627 and 1656. The monument is famous for its acoustic properties.