I slamic monuments are marked by arches, vaults, domes and towers, formal gardens, fountains  and inscriptions from the Quran.The most famous of  them in India is the Taj Mahal at Agra, the mausoleum dedicated by the Mughal emperor Shah Jehan to his wife Mumtaz Mahal. It was designed by Ustad Isa Afandi, built by 20,000 workmen of various nationalities, with white marble, red sandstone and precious stones.  It has a lofty white dome over the twin tombs of Shah Jehan and Mumtaz Mahal, which are surrounded by a high marble filigree screen. Other features are a tall archway and stretches of formal gardens.  Older still is Humayun's tomb at Delhi, with a huge dome, arched entrance and a neatly laid-out garden. Near Agra there also lies the city of Fatehpur Sikri built by Emperor Akbar, containing the white, marble tomb of Sheikh Salim Chisti.The Red Fort at Delhi, built by Shah Jehan, with its courts Diwan-i-Aam and Diwan-i-Khas, epitomizes late Mughal art. The tomb of  Emperor Aurangazeb's queen in Aurangabad is a small-scale prototype  of the Taj Mahal. Apart from the Mughals,  other Islamic dynasties have built their monuments  in India. The Qutab Shahi dynasty of Deccan built the Charminar in Hyderabad, a central square structure with lofty arched side-entrances, and four graceful minars on top. Asadud-Daula built the Imambara in Lucknow, a structure of massive proportions, with an impressive entrance called Rumi Darwaza. It contains the largest maze in India, the Bhul Bhulaiya. Qutab-ud-din Aibak's son and successor Iltutmish completed the tall tower in Delhi famous as the  Qutab Minar. In the Qutab Minar grounds stands the Quwwat-ul-Islam mosque, and an Ashokan pillar of iron which is still rust-free. Siri Fort, Lodi Gardens, Hauz Khas, Tughlakabad Fort and Safdarjung's Tomb are other instances of Islamic monuments in Delhi.