Islamicpix: Adnan Alavi presents photographs of mosques around the world, with a few historical notes.
Mosque: Tore Kjeilen explains the significance of the mosque to Muslims, its history, development and use, in an article for the Encyclopaedia of the Orient.
Mosque of Amr Ibn El-As: The Egyptian Tourism Ministry provides an illustrated history and description of the oldest mosque in Egypt, founded in 642 AD and rebuilt several times subsequently.
Mosques: Great Buildings Online provides images and information on famous mosques in Turkey, Syria and North Africa.
Mosques Around the World: IslamiCity presents photographs of outstanding mosques, both historic and modern, arranged by continent.
Saigon's Mosque: Photographs and brief history of this mosque built in 1935 by Indian Muslim traders.
Sinan Mosques in Istanbul: Chuck Newman's photographs of his tour around the mosques designed by the famed 16th-century architect.
Wikipedia: Great Mosque of Djenné: Information on the world's largest mud-brick building, in Mali. Sections on its history, design and significance, plus pictures.
Wikipedia: Suleiman Mosque: Illustrated history and description from the online collaborative encyclopedia of this grand mosque in Istanbul, built on the order of Suleiman I to a design by Sinan which reflected the nearby Hagia Sophia.