The Kaaba, Mecca, Saudi Arabia

Islam's holiest site, toward which Muslims worldwide pray five times a day. Millions of pilgrims circle it every year during Hajj, a pillar of Islam obligatory at least once for every Muslim who is physically and financially able.

Al-Masjid an-Nabawi, Medina, Saudi Arabia

The Prophet's Mosque, built on the site of Muhammad's home and burial place, and the second-holiest site in Islam after Mecca.

The Western Wall, Jerusalem

The last remaining retaining wall of the Second Temple, and the holiest site where Jews are permitted to pray. Visitors tuck written prayers into its cracks, a tradition observed for centuries.

The Dome of the Rock, Jerusalem

Built atop the Temple Mount/Haram al-Sharif, this gold-domed shrine marks the site from which Muslims believe Muhammad ascended to heaven during the Night Journey (Isra and Mi'raj). The same plateau is revered in Judaism as the site of both Temples and the binding of Isaac.

Church of the Holy Sepulchre, Jerusalem

Considered by many Christian traditions to contain both Golgotha (the site of the crucifixion) and Christ's tomb, making it one of Christianity's most sacred pilgrimage destinations.

Mount Sinai, Egypt

Traditionally identified as the mountain where Moses received the Ten Commandments, revered across Judaism, Christianity, and Islam. St. Catherine's Monastery at its base is one of the oldest continuously inhabited Christian monasteries in the world.

Karbala and Najaf, Iraq

Among the holiest cities in Shia Islam. Karbala holds the shrine of Imam Husayn, grandson of the Prophet, and Najaf holds the shrine of Imam Ali, drawing millions of pilgrims especially during Ashura.