structural:reformatting, structural:scholar_edition, structural:summarization
Characteristic features and styles

A common feature in mosques is the minaret, the tall, slender tower that usually is situated at one of the corners of the mosque structure. The top of the minaret is always the highest point in mosques that have one, and often the highest point in the immediate area. The first mosques had no minarets, and even nowadays the most conservative Islamic movements, like Wahhabis, avoid building minarets, seeing them as ostentatious and unnecessary. The first minaret was constructed in 665 in Basra during the reign of the Umayyad caliph Muawiyah I. Muawiyah encouraged the construction of minarets, as they were supposed to bring mosques on par with Christian churches with their bell towers. Consequently, mosque architects borrowed the shape of the bell tower for their minarets, which were used for essentially the same purpose – calling the faithful to prayer.

Domes have been a hallmark of Islamic architecture since the 7th century. As time progressed, the sizes of mosque domes grew, from occupying only a small part of the roof near the mihrab to encompassing all of the roof above the prayer hall. Although domes normally took on the shape of a hemisphere, the Mughals in India popularized onion-shaped domes in South Asia and Persia.

The prayer hall, also known as the musalla, has no furniture; chairs and pews are absent from the prayer hall. Prayer halls contain no images of people, animals, and spiritual figures although they may be decorated with Arabic calligraphy and verses from the Qur'an on the walls.

Usually opposite the entrance to the prayer hall is the qibla wall, which is the visually emphasized area inside the prayer hall. The qibla wall is normally set perpendicular to a line leading to Mecca. Worshipers pray in rows parallel to the qibla wall and thus arrange themselves so they face Mecca. In the qibla wall, usually at its center, is the mihrab, a niche or depression indicating the qibla wall. Usually the mihrab is not occupied by furniture either. Sometimes, especially during Friday prayers, a raised minbar or pulpit is located to the side of the mihrab for a khatib or some other speaker to offer a sermon (khutbah). The mihrab serves as the location where the imam leads the five daily prayers on a regular basis.

Mosques often have ablution fountains or other facilities for washing in their entryways or courtyards. However, worshipers at much smaller mosques often have to use restrooms to perform their ablutions. In traditional mosques, this function is often elaborated into a freestanding building in the center of a courtyard. Modern mosques may have a variety of amenities available to their congregants and the community, such as health clinics, libraries and gymnasiums.