Mecca is considered the holiest city in Islam, as it is home to the Kaaba and Al-Masjid Al-Ḥarām. Only Muslims are allowed to enter this place. The area of Mecca, which includes Mount Arafah, Mina and Muzdalifah, is important for the Ḥajj. As one of the Five Pillars of Islam, every adult Muslim who is capable must perform the Hajj at least once in their lifetime. Hajj is one of the largest annual Muslim gatherings in the world, second only to pilgrimages to the mosques of Husayn ibn Ali and his half-brother Abbas in Karbala, Iraq, with attendance reaching 3 million in 2012.
Medina
The Prophet's Mosque is located in Medina, making the city the second-holiest site in Islam, after Mecca. Medina is the final place-of-residence of Muhammad, and where his qabr is located. In addition to the Prophet's Mosque, the city has the mosques of Qubā’ and al-Qiblatayn.
Levant (''Ash-Shaam'')
Greater Syria is a region that extends from Syria in the north to Israel in the south. It includes the cities of Jerusalem and Hebron.
Jerusalem
According to mainstream Sunni and Shi'ite traditions, Al-Masjid Al-Aqṣā is located in Jerusalem. The mosque is held in esteem by the entire Muslim community, due to its history as a place of worship that is intertwined with the lives of many Biblical prophets, such as Abraham, Dawud, Sulaimon, Ilyas and ʿĪsā ibn Maryam, as well as for its special status. The mosque comprises in size, with the capacity to accommodate in the region of 5,000 worshipers. The mosque was the first direction of prayer in Muhammad's lifetime, before the Kaaba in Mecca, and Muhammad was believed to have been taken by the miraculous steed, that is the Buraq, to visit Al-Aqsa Mosque, where he prayed, and was then taken to the heavens, in a single night in the year 620CE that is known as Al-Isrāʾ wal-Miʿrāj. References to it exist in Surah Al-Ma'idah, Al-Isra', Al-Anbiya and Saba' : in the Qur'an.
Damascus
Damascus, and particularly the Umayyad Mosque in the Old City, is considered by some Muslims to be the fourth holiest site in Islam. One of the four authorized copies of the Quran was kept here, and the head of Yahya ibn Zakariyya is believed to be in the shrine. One of the minarets is dedicated to Jesus, and it is believed he will return to it to judge the world, and assist a figure called Al-Mahdi. It is believed that after the end of the world prayers will continue for forty years in the mosque, and that prayers in the mosque are considered to be equal to those offered in Jerusalem.
Hebron
Hebron is a Palestinian city in the southern West Bank, south of Jerusalem, considered by many Muslims to be the fifth holiest city in Islam. Its Arabic names, Khalil Ar-Rahman and Al-Khalil, stems from the belief that it was the city Abraham settled in. Within the city lies the Sanctuary of Abraham, the traditional burial site of the biblical Patriarchs and Matriarchs, and the Ibrahimi Mosque built on top of the tomb to honor the prophet. Muslims believe that Muhammad visited Hebron on his nocturnal journey from Mecca to Jerusalem to stop by the tomb and pay his respects. In the mosque in a small niche there is a left footprint, believed to be from Muhammad.
The Sinai peninsula is associated with Aaron and Moses, who are also regarded as Prophets. In particular, numerous references to Mount Sinai exist in the Quran, where it is called Ṭūr Sīnāʾ, Ṭūr Sīnīn, and aṭ-Ṭūr and al-Jabal. As for the adjacent Wād Ṭuwā, it is considered as being muqaddas, and a part of it is called Al-Buqʿah Al-Mubārakah.
Europe
The Eyüp district in the Turkish city of Istanbul is considered the fourth holiest site by some sources. Abu Ayyub al-Ansari, the friend and standard-bearer of Muhammad, is said to be buried in the Eyüp Sultan Mosque. Ottoman believers considered this site to be third holiest in the world, after Mecca and Medina. Ottoman Sultan/Caliphs acceded to their title in a ceremony in the Eyüp mosque, as this location was more sacred than any location in the capital, being the tomb of a companion of the prophet provided a "blessing bestowal" from the closest circle of Muhammad. Eyüp, who died at the unsuccessful siege on Constantinople, provided a reminder that the Ottomans succeeded where earlier Islamic armies, led by a companion of the prophet, failed.
Africa
Harar
According to UNESCO, Harar in eastern Ethiopia is "considered 'the fourth holy city' of Islam" with 82 mosques, three of which date from the 10th century and 102 shrines.
Kairouan
The most important mosque in Kairouan is the Great Mosque of Sidi-Uqba. It has been said that seven pilgrimages to this mosque is considered the equivalent of one pilgrimage to Mecca. After its establishment, Kairouan became an Islamic and Qur'anic learning centre in North Africa. An article by Professor Kwesi Prah describes how during the medieval period, Kairouan was considered the fourth holiest city in Islam after Mecca, Medina and Jerusalem. Today, many consider the city as the fourth holiest in Islam.
