This trip doubles up on historic Slovenian gems. First, we'll head to the Postojna Caves, one of the longest cave systems in Europe. But you won't just be exploring on foot - you'll climb aboard the world's first cave railway to marvel at thousands of stalagmites and stalactites. Then, it's on to the nearby Predjama Castle, an almost impregnable 13th Century fortress, hewn from a 123m-high cliff face. You'll get an insight into medieval life with a walk through the armoury, chapel, kitchen and torture chamber, and learn the legend of Erazem Predjamski - Slovenia's answer to Robin Hood.