The Marikostinovo Mud Resort is located 2 km from the village of. Marikostinovo, 13 km from Petrich and 1 km from the Struma River. It is located at 80 m above sea level. The combination of mineral water and healing mud is a kind of valuable natural wealth, which is similar to the healing factors in Hevis – Hungary and Piešťany in Czechoslovakia. These natural resources of the spring have been known since ancient times.