The Selimiye Mosque in Edirne has been recently included on the Unesco World Heritage List. The mosque was commissioned by Sultan Selim II and was built by architect Mimar Sinan between 1568 and 1574. It was considered by Sinan to be his masterpiece and is one of the highest achievements of Islamic architecture.
In this mosque Sinan employed an octagonal supporting system that is created through eight pillars incised in a square shell of walls. The four semi domes at the corners of the square behind the arches that spring from the pillars, are intermediary sections between the huge encompassing dome (31.25m diameter with spherical profile) and the walls.