RIver-basin: Ipeľ

Ottergrund – the highest situated water reservoir (801 m above sea level) in Banská Štiavnica ore region, above it there is the highest situated settlement in the Štiavnické Hills. It was built up before 1746 and keeps 7.000 m³ of water. Its water was used for running pumping devices in the shaft Schmidtenrinn in the town area of Horná Resla.