Masjid e Tooba or Tooba Mosque is located in Karachi, Sindh, Pakistan. Locally, it is also known as the Gol Masjid. Masjid e Tooba was built in 1969 in Defense Housing Society, Karachi is nineteenth largest mosque in the world.

Masjid-e-Tooba

It is located just off main Korangi Road. Masjid e Tooba is often claimed to be the largest single dome mosque in the world. It is also major tourist attraction in Karachi. Masjid e Tooba is built with pure white marble. The dome of the Masjid e Tooba is 72 meters (236 feet) in diameter, and is balanced on a low surrounding wall with no central pillars. Masjid e Tooba has a single minaret standing 70 meters high. The central prayer hall has a capacity of 5,000 people. It has been built keeping acoustics in mind. A person speaking inside one end of the dome can be heard at the other end. This mosque was designed by Pakistani architect Dr Babar Hamid Chauhan.

source : http://thewondrous.com