This is Latvia’s first major hydroelectric power plant, and construction along the right bank of the Daugava began in 1936.  The plant was designed by the architect Eižens Laube.  The first hydro-aggregate (17 MW of capacity as the largest plant in Latvia) was switched on in 1939.  A second round of construction occurred between 1976 until 1979, the result being a new building on the left bank of the Daugava, increasing the capacity of the plant to 260 MW.  Another round of reconstruction occurred between 1998 and 2001 on the left bank of the Daugava (the HES-2 plant).  The Energy Museum is now there.