Masalli is known for its mineral springs, the most famous of which is Istisu (literal meaning 'hot water'). This thermal spring appears in several places along the Vilashchay River bank on the Dombal hillside at 1,650 metres above sea level. The water comes out hot (about 69 degrees) from a depth of 90-250 m and is used to treat many diseases. Today, there's a sanitorium called Fatima Zahra, as well as guesthouses, teahouses and other tourist facilities.

Istisu Settlement, Gariblar Village, Masalli District.