Arbaeen, the 40th day after the martyrdom anniversary of Imam Hussein (AS), the third Shia Imam, falls on Tuesday this year.
Millions of pilgrims from Iraq and other countries around the world have gathered in Karbala for Arbaeen.
Bayn al-Haramayn, literally meaning between the two shrines, is the distance of 378 meters between the holy shrine of Imam Hussein (AS) and the holy shrine of Hazrat Abbas (AS) in Karbala.