The dams in River EskilstunaÃ¥n at Hyndevad regulate the water level in Lake HjÃ¤lmaren. Around 1880 when they were built, and the lake lowered, the river bed was temporarily laid dry. A major prehistoric sacrificial site was discovered, and luckily geologist Otto Gumaelius was there to document it. (He used the finds to date events in the watershed’s recent quaternary geology.) The landscape has since been thoroughly messed up at Hyndevad, but still I went there yesterday to get a feeling for the place. I wish I had the resources to lay a few lakes and river stretches dry.