The area around Trigrad has awesome gorges and caves. Trigradsko zhedrelo (the Trigrad gorge) has sheer gray walls overhanging a foaming river, which vanishes into a cave called Dyavolsko gârlo, or Devil's Throat. It's pretty impressive: the size of two cathedrals, and very dimly lit. Yet it is far from matching the Škocjan cave in Slovenia for size or river noise.
Chudnite Mostove, or Miraculous bridges, are rock formations forming natural bridges over a narrow stream. They are set near Zabârdo, a village meant to be famous for its weavers (but we didn't see any, though we tried asking many locals). There is also an icy cave which never defrosts, even in the peak of the summer. It's a very natural place, ideal for walking, with conifer forests stretching to the horizon on the hilly landscape.