In the former stables prehistoric finds of two spices of mastodon, predecessors of today's elephant, are exhibited. They were discovered in 1964 in Škale near Velenje.
Mastodons strode in Šaleška dolina valley about two million years ago. The most interesting item is a plastic mastodon in natural size, made from polyester by academic sculptor Dora Novak.
The bones of mastodon are exhibited in the glass cases. On the wall hangs an impressive oil painting by Tomaž Perk showing Šaleška dolina valley in the beginning of the ice age.