It is strictly personal, but Škocjan Education Trail is one of the most spectacular one in the country. And even though you don't need to be very fit to manage this trail, you will be highly rewarded. I can't emphasize this enough, but for everyone on the lazy side, I assure you, it is not a hard walk.
The trail is circular and explanatory signs with illustrations, photographs and a short text begin in front of the Information Centre in Matavun, that is where tickets for Škocjan Caves tours are purchased. With signs you'll be able to understand the natural phenomena and cultural heritage. The walk will take you through villages Škocjan, Matavun and Betajna, into the karst doline, huge sink hole, and to the edge of the abyss. Amazing vies, tranquil nature and antique villages. A must do while in Slovenia. And absolutely free.
After writing a blog in Slovenian language for 10 years I have finally come to my sense and started writing one in English as well.