Sushica - this is one of the richest in caves regions in Bulgaria. The Ahmetiova Dupka Cave is a real pearl. It is provided with all utilities except light. However, this is not an obstacle if you want to see its beauties, gathered in an only hall with a length of 40 metres. At the very entrance you are welcomed by a gigantic, 5-meter-tall stalactone, and from here on no words can describe the countless formations. The Ivanova Voda (Ivan's Water) and Druzba (Friendship) Caves are a true challenge for the speleologists. They are abyss caves, with depths respectively 131m and 211m. A few hundred meters below the Martsiganitsa Hut is the Topchika Cave. There are no cave formations in it, but some primitive rock drawings were found here. Flint tools were also found here during some archaeological work, as well as a whole skeleton of a cave bear. The upper hall is connected to a lower hall through a 50m. abyss. Iamata (The Pit) and Hralupata (The Hollow) are among the other interesting caves. They are situated to the north of Topchika, and there you can see some rare cave formations, like helictites.