 As a result of Imam al-Rida (a.s)'s travel from Medina to Merv, in which he crossed a major part of Iran, there are many qadamgahs attributed to him.The best known qadamgah attributed to the ali al rida (a.s) is the one in Nishapur which was constructed at the command of Shah 'Abbas in 1020/1611 over the relics of another building.It is widely believed that there is a human footprint on a black stone installed inside the building which is attributed to Imam al-Rida (a).