In the Old City, the Mughals and the Turkic rulers constructed several architecturally significant buildings, such as the Jama Masjid—India's largest mosque built in 1656 and the Red Fort. Three World Heritage Sites—the Red Fort, Qutub Minar and Humayun's Tomb—are located in Delhi. Other monuments include the India Gate, the Jantar Mantar—an 18th-century astronomical observatory—and the Purana Qila—a 16th-century fortress. The Laxminarayan Temple, Akshardham temple, Gurudwara Bangla Sahib, the Baháʼí Faith's Lotus Temple and the ISKCON temple are examples of modern architecture. Raj Ghat and associated memorials houses memorials of Mahatma Gandhi and other notable personalities. New Delhi houses several government buildings and official residences reminiscent of British colonial architecture, including the Rashtrapati Bhavan, the Secretariat, Rajpath, the Parliament of India and Vijay Chowk. Safdarjung's Tomb is an example of the Mughal gardens style. Some regal ''havelis'' (palatial residences) are in the Old City. Lotus Temple is a Baháʼí House of Worship completed in 1986. Notable for its flowerlike shape, it serves as the Mother Temple of the Indian subcontinent and has become a prominent attraction in the city. 