Dubrovnik.

We spent a beautiful couple of hours on a double-decker bus last weekend, winding through the mountains and up the coast to Croatia. The Grand Imperial Hotel welcomed us with a sunny balcony and sweets, and the entire city of Dubrovnik was a gem: lots of winding streets, endless staircases, a sea wall to climb (I mostly clung onto the sides and tried not to look over the sheer drops, but people without fear of heights seemed to enjoy it...), a delicious vegetarian restaurant (Nishta, highly recommended), and cliffside bars. And cats. More cats.