Slovenia for sure
has so many things, alps, sea, caves, lakes, rivers, spas, canyons, beautiful country side...
you can be hiking up the alps in the morning and swimming in the evening.
I can't agree with bellow answer. When I was there trains were always spot on time. If they are late it's only for around 5 minutes. Yes, there's only 1 or two trains leaving for a destination in 1 hour but what can you expect in a country with 2m people?