Bayn al-Haramayn — literally "between the two sanctuaries" — is the 378-metre stretch of marble between the Husayn and Al-Abbas shrines. It was widened and paved in white stone after 2003 to handle the swelling pilgrim crowds, and now functions as a vast outdoor mosque, a meeting place, and a procession route all at once.
In the cooler hours after sunset, families spread blankets on the marble and eat together. During Arbaeen, the plaza is almost impassable: rivers of pilgrims flow between the shrines, some carrying flags and tabarruk (offerings of food and water for fellow walkers). It is the single most photographed view in Karbala, with both golden domes framing the crowds.