Istiqlal Mosque, or Masjid Istiqlal, in Jakarta, Indonesia  is the largest mosque in Southeast Asia in term of capacity to accommodate people.

Istiqlal-Mosque

However in term of building structure and land coverage, Istiqlal is the largest in Southeast Asia and fourth largest in the world. This national mosque of Indonesia was build to commemorate Indonesian independence, as nation’s gratitude for God’s blessings; the independence of Indonesia. Therefore the national mosque of Indonesia was named “Istiqlal”, an Arabic word for “Independence”.

source : http://thewondrous.com