Badab-e Surt (Persian: باداب سورت‎) is a natural site in Mazandaran Province in northern Iran, located 68 kilometers north of city of Damghan, 95 kilometers South of city of Sari, and 7 kilometers west of Orost village. It comprises a range of stepped travertine terrace formations that has been created over thousands of years as flowing water from two mineral hot springs cooled and deposited carbonate minerals on the mountain side. The red color of travertine terraces are due to iron carbonate.