Lake Ursu (Bear Lake), Sovata

Lake Ursu lies in the Sovata-Băi resort, in the northern part of the town of Sovata, in the Praid-Sovata Depression at the south-western foot of the Gurghiu Mountains. The lake formed on 27 May 1875 at 11 a.m., when a cloudburst blocked a sinkhole and the water of two small streams collected in a hollow on the salt massif. It reached its present shape by 1881. Its name comes from its outline, which resembles a spread bearskin. The town's statute gives it an area of about 4 hectares (40,235 square metres), a shoreline of 1,180 m and a maximum depth of more than 18 m. The lake shows heliothermy, discovered in 1901: fresh water from the streams stays on the surface without mixing with the salt water below and acts as an insulating layer, so the salt water at a depth of 1-2 m is heated by the sun more than the surface water and can exceed 40 °C in summer. In 2019 the lake was entered in the book of records as the largest heliothermal lake in the world. The lake began to be used at the end of the nineteenth century, when the landowner Sófalvi Illyés Lajos built a villa on its southern shore in 1894 and in 1901 founded the Sovata resort. The salt water and the mud from the lake beds are used in the resort's spa treatments. Bathing in the lake is allowed during the summer season, for a fee. The lake is a natural monument and part of the „Lacul Ursu și arboretele de pe sărături” nature reserve (79 ha, IUCN category III, designated by Law no. 5/2000), which also includes the Aluniș, Paraschiva, Mierlei, Roșu and Verde lakes and the sessile oak, oak, beech and spruce woods growing on the salt massif. In 2015 the „Drumul Sării” (Salt Road) was laid out around the lake, an educational trail with panels on the local flora and fauna and a 28 m observation tower.