Minarets (Arabic and Urdu: minra pl. minar) are distinctive architectural features of Islamic mosques. They are generally tall, graceful spires, with onion-shaped crowns, usually either free standing or much taller than any surrounding support structure.
The main function of the minaret is to provide a vantage point from which the muezzin can call out the adhan, calling the faithful to prayer. However, it should be noted that in most modern Mosques, the adhan is called not in the minaret, but in the musallah , or prayer hall, via a microphone and speaker system. Therefore, the role of the minaret is now largely for traditional and decorative puposes.
Minarets have been described as the "gate from heaven and earth", and as the Arabic language letter alif (which is a straight line).
Minarets, at the Encylopedia of the Orient
Minaret Photo Gallery