Masjid al-Haram (Mecca) — closed to non-Muslims
FIRST holy site of Islam. World's largest mosque (~1.5 million worshippers capacity, expanding to 2.5 million). At its centre: the Ka'ba (cube 13×11×15 m draped in black/gold kiswa, geographical point towards which 1.9 billion Muslims pray 5×/day). Black Stone (al-Hajar al-Aswad) in a silver corner. Maqam Ibrahim. ZamZam spring (legendary uninterrupted spring water since Abraham/Hagar). Tawaf: 7 circumambulations around the Ka'ba. Sa'y: 7 round trips between Safa and Marwa. Mecca is CLOSED to non-Muslims (signs 30 km before).
The Ka'ba is draped in a new kiswa every 9 Dhul-Hijja (Hajj eve) — the old one is cut up and given to Muslim dignitaries worldwide. Weighing ~650 kg, the kiswa is woven in Mecca at a royal manufactory (Ka'ba Kiswa Factory) in black silk + gold thread. The Black Stone is actually several fragments — the original was partially destroyed during 11th century attacks. The ZamZam spring delivers 11-18 litres/second uninterruptedly for ~4,000 years according to tradition.
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