We visited Náměšť nad Oslavou as there was a folk music festival with many collateral activities suitable for children.
Among other things we also visited the hydroelectric power at the nearby Dalešická přehrada. It's run by the sponsor of the festival, the monopolistic ČEZ, often accused of influencing politics in this country. Unfortunately for us, the guide spent too much time explaining us what political parties are wrong for the country (and therefore for ČEZ), so we had to skip the most interesting bottom levels of the plant in order to not miss the boat ride.
Finally, at the end of the day, we came across this neat waste-water treatment plant of Náměšť: