The Kuurmanpohja-Saarenoja Stone Age dwelling site is a natural and cultural site of Saimaa Geopark. The Kuurmanpohja-Saarenoja area is located southeast of First Salpausselkä near the national border. The area has large elevation differences and valleys formed in bedrock fracture zones, which were 11,000 years ago narrow bays of the ancient Baltic Sea, or the Yoldia Sea. About 10,800 years ago, the ocean connection was cut off due to land uplift, and the freshwater phase of Ancylus Lake began in the Baltic Sea.