01. Quba Mosque, Saudi Arabia
First Built: 622
The  designation of the oldest mosque in the world requires careful use of  definitions, and must be divided into two parts, the oldest in the sense  of oldest surviving building, and the oldest in the sense of oldest  mosque congregation. Even here, there is the distinction between old  mosque buildings that have been in continuous use as mosques, and those  that have been converted to other purposes; and between buildings that  have been in continuous use as mosques and those that were shuttered for  many decades. In terms of congregations, they are distinguished between  early established congregations that have been in continuous existence,  and early congregations that ceased to exist (wikipedia). 09 More after the break...
 

