Jama Masjid, commonly known as the Jama Masjid of Delhi, is the principal mosque of Old Delhi in India. Commissioned by the Mughal  Emperor Shah Jahan

Jama-Masjid

, builder of the Taj Mahal, and completed in the year 1656 AD, it is the largest and best-known mosque in India and ninth largest mosque  in the world. It lies at the origin of a very busy central street of Old Delhi, Chandni Chowk. The later name, Jama Masjid, is a reference to the weekly Friday noon congregation prayers of Muslims, Jummah, which are usually done at a mosque, the “congregational mosque”. The courtyard of the mosque can hold up to twenty-five thousand worshipers.

source : http://thewondrous.com