The Lake of Kastoria, or officially lake Orestiada, is without any doubt one of the most beautiful lakes of Greece. It has been declared as a Monument of Natural Beauty by the Ministry of Culture and it is a part of the European environmental protection network "Natura 2000". The area covered is more than 28 square kilometers, it is 630 meters above sea level and its maximum depth is 10 meters. The lake is supplied with water from streams and several sub-lake sources, while it is considered the second most productive lake in terms of fish in the country.

The mansions of Kastoria are built following the main Macedonian architectural techniques. Some of them are open to the public, such as the mansion of Nerantzis Aivazis that houses the Folklore Museum of the city. The mansion is located in Doultso, a district that includes some of the most famous buildings.

The Cave of the Dragon is located in the northern part of Kastoria, close to the lake of the region as well as the monastery of Panagia Mavriotissa. The main characteristic of the cave is the large number and variety of stalactites and stalagmites. It includes 7 underground lakes, 10 halls, and 5 passages.