What is a mosque?
Al-Azhar Mosque, Cairo (Egypt, 900s AD)
November 2016 - A mosque (MAH-SK) is a kind of building where people who follow the Islamic faith pray to God. The first mosques were built in the 600s AD, when the Arabs first conquered Jerusalem and other parts of West Asia. One of the earliest mosques is the Dome of the Rock in Jerusalem, which is built on the place where the Jewish Temple once stood.
Kairouan mosque (ca. 800 AD)
The architecture of mosques depends on where you are and when the mosque was built, and there are many different styles. Still, most important medieval mosques had a large open courtyard when you first came in, and then an inner prayer room. Inside the prayer room was a mihrab, a niche or hole in the wall which showed the direction of Mecca (because all Muslims pray facing the holy city of Mecca, where Mohammed was from). If you were in Baghdad, Mecca is to the west, but if you were in Jerusalem, Mecca's to the south, and if you were in Kairouan or Cordoba, then Mecca's to the east.
Most mosques also had a minaret - a tall tower. The muezzin (moo-EZZ-inn) climbed up the steps inside this tower five times every day to sing out the call to prayer. In this way everybody knew when it was time to pray (and also when it was time to go to school and so on). This was very important because there weren't any clocks yet.
The great mosque in Cordoba, Spain was also built around this time. By 800 AD, people in Africa had converted to Islam and built the Great Mosque at Kairouan, in Tunisia. And the Arabs built great mosques at their capital, Baghad, in Iraq.
Here's a very short video of men praying in a mosque in India
By 1100 AD, people in India were converting to Islam, and they built mosques there as well - but in a different style. Even further east, people built mosques in Central Asia and in China. After the Ottoman Empire captured Constantinople in 1453 AD, the sultans changed the great Christian churches there into mosques as well. The most famous is Hagia Sophia.