A mosque is a place of worship for followers of Islam.I was personally in Istanbul and I visited both Hagia Sophia and Blue Mosque. As you can see in the pictures, it truly deserves to go to visit these magnificent buildings that are of great importance.
The mosque serves as a place where Muslims can come together for salat (prayer) (Arabic: صلاة, ṣalāt) as well as a center for information, education, and dispute settlement. The Imam leads the prayer.
They have developed significantly from the open-air spaces that were the Quba Mosque and Al-Masjid al-Nabawi in the 7th century. Many mosques have elaborate domes, minarets, and prayer halls. Mosques originated on the Arabian Peninsula, but are now found in all inhabited continents.
Large mosques play sometime a political role as well. In Islamic countries like Pakistan, Iran and Iraq (after 2003), political subjects are preached by imams at Friday congregations on a regular basis. In other Islamic countries, imams are usually banned from mentioning political issues.