The Dlouhé Stráně Lower Reservoir in the Jeseníky Mountains is far more than just a pretty mountain lake — it is the lower basin of one of the Czech Republic's most impressive pumped-storage hydroelectric power stations. Sitting at 825 metres above sea level, this triangular stretch of calm water surrounded by forest offers a wonderfully peaceful atmosphere with an intriguing industrial secret beneath the surface.

The reservoir covers 16.3 hectares and is held back by a 306-metre-long, 58-metre-high dam that itself is worth a look. The shores are lined with trees, making the walk around the water's edge a pleasant experience in any season. The wild Divoká Desná river flows through the reservoir, giving the landscape a lively, mountain character. In autumn the surrounding forests put on a spectacular show of colour, while summer brings cool shade and tranquillity.

How to get there

• Kouty nad Desnou — marked trail along the Divoká Desná valley, easy walking, roughly 30–40 minutes on foot.

Practical information

• The reservoir serves an active technical function; keep away from all hydro-engineering structures and respect any restricted zones.
• The water is home to salmon and carp.

Two underground tunnels — each 1.5 km long and 3.6 metres in diameter — connect this lower reservoir with the upper one high on the mountain, pumping water up and down to store and generate electricity. Engineering on a truly mountain scale.