Most mosques have two to six of them. From a balcony on the minaret, a muezzin, or crier, calls the faithful to prayer five times each day. Some larger minarets, like the ones at the Blue Mosque in Istanbul, have several balconies on every tower where several muezzins can stand and make their call.
Minarets come in a variety of shapes.
Some are round or square and others are many-sided. Most contain an inner staircase and the majority are built of stone or brick. Minarets are perhaps the most common feature of Islamic architecture. The ancient Lighthouse of Alexandria, Egypt, completed in the 200's BC, may have been the form from which the minaret originally was derived. They are thought to have symbolic meaning as well.