Millions of Muslims have gathered in Mecca, marking the beginning of the five-day Hajj pilgrimage—the world's largest annual religious gathering. It is year 1446 in the Islamic calendar. Pilgrims are expected to retrace the steps of the Prophet Muhammad,

Here is a look at the hajj, one of the largest mass gatherings in the world, which starts in Saudi Arabia on Wednesday.

Saudi Arabia has announced drastic changes for the 2025 Hajj pilgrimage that begins today, including new rules prohibiting children from accompanying pilgrims, and prioritizing pilgrims traveling for the first time.