Wawel Castle, Krakow Poland

Wawel Castle is definitely worth the walk from the main square, it’s a UNESCO World Heritage site. An unusual mix of features: chapels, treasury, crown jewels, colonnaded courtyards, tombs… it has been variously trashed and rebuilt over the centuries. Its current form is certainly pleasing and it offers a good vantage point from which to look over the Vistula river and the newer part of the city.

You can get a taxi most of the way but the walk in summer is nicer.