Minaret

[Sarah]

A slender, lofty tower attached to a mosque and surrounded byone or more projecting balconies, from which the summon to prayer iscried by the muezzin.

[Sarah]

Tower near to, or built into, the structures of a mosque, which is used by the muezzin to call out the adhan in order to make people to come to prayers in Islam.
Distinctive architectural features of Islamic mosques. Minarets are generally tall, graceful spires, with onion-shaped crowns, usually either free standing or much taller than any surrounding support structure.

Minarets basically consist of three parts:
Base - Usually the ground underneath the towering minarets is excavated until a hard foundation is reached. Gravel and other supporting materials may be used as a foundation, and it is rare that one is built directly upon ground-level soil.
Shaft - Single minarets with in an elongated body are either conical (tapering at the top), cylindrical (a circular shaft) or polygonal (with edges, as opposed to cylindrical). Stairs circle the shaft in a counter clockwise fashion, providing a necessary structural support for highly elongated shafts.
Gallery - A balcony encircles the upper section where the muezzin will give the call to prayer. It is covered by a roof-like canopy and adorned with ornamentation, such as decorative brick and tile work, cornices, arches and inscriptions. Originally plain in style, a minaret's origin in time can be determined by the level of the gallery's ostentation.

[Jessica]

a tall, thin tower on or near a mosque (= a Muslim holy building) from which Muslims are called to pray

[Sonia]

A tall slender tower, typically part of a mosque, with a balcony from which a muezzin calls Muslims to prayer.