The power plant was selected as one of the seven wonders of the Czech Republic in a 2005 poll.
The difference in elevation between the upper and lower reservoirs is 510.7 meters.
The facility can produce up to 650 MW of power in turbine mode.
Construction required removing the original peak of the Dlouhé stráně mountain to create the basin floor.
The upper reservoir is lined with a specialized asphalt concrete layer to ensure water tightness.
The entire power plant is located underground in caverns carved out of the rock mass.
Dlouhé stráně is a pumped-storage hydroelectric power plant located in the Jeseníky Mountains, featuring an upper reservoir perched at an elevation of 1,350 meters. The facility is recognized as the largest hydroelectric power station in the Czech Republic and holds the distinction of having the largest pump-turbine unit in Europe. It operates by moving water between two reservoirs at different altitudes to balance the national energy grid. The upper reservoir is a man-made basin constructed on top of the Mravenečník mountain, requiring the summit to be leveled during construction. Visitors access the site via a combination of chairlift and shuttle bus, as private vehicle access to the upper reservoir is restricted. The facility is a functional industrial site that doubles as a technical tourist attraction offering panoramic views of the surrounding Hrubý Jeseník range. The reservoir has a maximum capacity of 2.7 million cubic meters of water.
The edge of the upper reservoir wall provides the most expansive 360-degree view of the Jeseníky mountain range.
Bring a windbreaker even in summer, as the temperature at the summit is significantly lower than in the valley.
Book your guided tour reservation well in advance, as group sizes for underground visits are strictly limited.
Wear comfortable, closed-toe walking shoes to navigate the transition between the shuttle stop and the reservoir edge.
Do not attempt to hike the entire ascent from the valley floor if you have limited time, as the distance is substantial and requires high physical endurance.
Tours require advance booking; access is occasionally restricted during extreme weather conditions or facility maintenance.
Safety helmets must be worn during the underground technical tour; follow all guide instructions regarding restricted industrial zones.
