Red Lake

Red Lake is a natural dam lake in Harghita County, Romania. It is located in the Hășmaș Mountains, on the upper course of the Bicaz River, and lies at the foot of the Hășmașul Mare Peak, near the Bicaz Gorge, at a distance of 26 km from Gheorgheni and 30 km from Bicaz.

The lake formed following the collapse of a slope due to the earthquake of January 23, 1838 at 18:45, measuring 6.9 magnitude on the Richter scale, VIII intensity. The landslide blocked the course of the Bicaz River and the lake formed behind this dam.: 124 

According to measurements in 1987, the lake has a perimeter of 2,830 m, and covers an area of 11.4676 ha; the volume of water that accumulates is 587,503 cubic metres.

Source: Wikipedia