Lehnjakovi pragovi na Krki
V zgornjem toku je Krka tipična kraška reka s širokim zaledjem podzemnih pritokov in edina slovenska reka, v kateri se izloča lehnjak.
Lehnjak je biokemična sedimentna kamnina, ki nastane, ko voda, ki vsebuje kalcijev karbonat teče čez organske ostanke (liste, veje, tudi skelete živali) in se na njih izloča ter jih na ta način obda (inkrustira). Je močno porozna, lahka in luknjičava kamnina.
V zgornjem toku je kar 90 lehnjakovih pregrad, ki so najslikovitejše ravno na območju občine Žužemberk, pri Žužemberku in na Dvoru.Ob lehnjakovih pragovih so v preteklosti zgradili mnoge vodne mline in žage.
Sam zakladek je skrit v nekdanji Dvorski žagi. Ta je obratovala do začetka šestdesetih let 20. stoletja, leta 2003 pa je pogorela.
Tufa thresholds on Krka
In the upper stream, Krka is a typical karst river with a wide underground tributary and the only Slovenian river in which tufa is excreted.
Tufa is a biochemical sedimentary rock that is formed when water containing calcium carbonate flows over organic remains (leaves, branches, even animal skeletons) and excretes them by encrusting them. It is highly porous, light and holey stone.
In the upper stream, there are 90 tufa thresholds, which are most picturesque in the municipality of Žužemberk, near Žužemberk and Dvor. Many water mills and sawmills have been built at tufa thresholds in the past.
The cache is hidden in the former Dvor sawmill. It operated until the beginning of the 1960s, and burned down in 2003.