followed by Lake Aheru (234 ha). The southern part of Lake Võrtsjärv, with the area of 300 hectares, is also included within the borders of Valga County. Most of the lakes are quite shallow and not deeper than 10 m. The deepest lakes in the county are Udsu (30.2 m) and Petajärv (25 m), both located on the territory of Koorküla Lakes where the old valleys have been filled by the sediments from the Ice age. There are four official swimming places – the beach of Riiska Lake and Vanamõisa Lake in Tõrva, the beach of Lake Pühajärv in Otepää and the beach on the sides of Pedeli River in Valga.