The Jamat Khana Masjid or Khilji Mosque is the earliest mosque in Delhi that continues to be used for worship. Built by Khizr Khan, son of Sultan Alauddin Khilji (Khilji Dynasty) in 1315-1325 AD, the mosque is the largest structure in the Nizamuddin Basti Dargah enclosure (Nizam-ud-Din Auliya Shrine Complex). Each of the three bays has a domed roof with the central one being the largest, as is the practice. Marble finials adorn the top the domes. The central bay and the entrance archway are embellished with bands of exquisite geometric motifs and Quranic inscriptions.