The last ice age moulded the landscape of South Võrumaa so that there are many lakes and valleys. Rõuge primeval valley, which is 10 km long and 52 metres deep, has seven lakes: Kahrila Lake, Tõugjärv, Ratasjärv, Kaussjärv, Rõuge Suurjärv, Liinjärv and Valgjärv. The lakes are connected by the River Rõuge or Ajo, which starts from the valley Tindiorg.
Tindiorg, Külmorg, Mõhkorg, Ööbikuorg, Tinopeetri, Hinni, Sikasoo and Järveotsa are the tributary valleys of Rõuge primeval valley. Ööbikuorg (Nightingale Valley), that borders the ancient fort is the most well-known. The valley is 300 m long and 12–15 m deep.
Useful information: In spring, when the European bird cherries bloom, the valley is filled with singing nightingales, that's also where the names comes from.