Skocjan cave
Took the train for a day trip like a proper tourist (although the real tourists go on by guided coach). The cave starts off nice but not revolutionary since I have visited 3 other caves recently, some nice stalactites and stalagmites, and a rather massive cavern - then I realise there is a difference - this is the first tour with an English speaking guide - but he almost rushes past these wonders, and upon turning the corner you forgive it - the cave opens up into an underground canyon, 150m high floor to ceiling, where the river has eroded away the limestone over quite some time...
Lamp lights show where the path meanders off into the distance, carved or fixed into the cliff side, into a slight mist, every bit evoking a scene from Lord of the rings or something, its fantastical.
So that was cool.