Lacul Ursu, or Bear Lake, holds a remarkable title — it's the largest heliothermal salt lake in the world, where water can reach a startling 35°C near the surface despite the cool Transylvanian climate. This natural phenomenon has drawn visitors for over a century, seeking relief in its warm, mineral-rich waters.

Formed in 1875 on a salt karst near the town of Sovata, the lake sits in gentle Transylvanian hillside scenery, its surface often steaming gently as fresh water from an inflowing stream floats atop the denser salt water below, trapping solar heat in the depths. Summer brings crowds of visitors floating in its buoyant, mineral-rich waters, while in cooler months the lake takes on a quieter, almost mystical atmosphere framed by the surrounding hills.

• Sovata town centre — easy walk, approx. 15-20 minutes to the lake shore
• Sovata Băi spa area parking — direct access to the lakeside facilities

• Surface salinity around 100 g/l, increasing to 220-300 g/l at depth
• Surface water (down to 2m) can reach 35°C in summer thanks to the heliothermal effect
• Swimming is paused for about an hour around midday to let the warm layer re-form
• Waters have been used therapeutically for over a century, recommended for fertility issues and rheumatic or inflammatory conditions

The lake's name comes from its silhouette, said to resemble a spread-out bearskin, though local legend tells of a fairy whose unrequited love for a shepherd gave birth to this extraordinary lake.