The said fish ponds, which were established at the beginning of the 20th century by the last owner of Lesná Manor with the idea of growing trout, but which have long been abandoned, are now refuge for a number of rare amphibian animals which reproduce here in large numbers. The shores of the ponds have been taken over by pioneer woods (aspen and willow), and in 2005 attracted the attention of our largest domestic rodent: the endangered European beaver. With these natural values in mind, the territory was declared a natural monument in 2012.
The circular educational trail, built in 2010 by ČSOP Sylva Lunae thanks to the NET4GAS Closer to Nature programme, is almost 2 km long and familiarises visitors with the life of aquatic animals. It also gives visitors the opportunity to watch these animals in their natural habitat. Those who are patient may even be able to take a peek into the life of the local beaver family from the hidden observation spot.