A spa town built on hot springs
Karlovy Vary (known historically by its German name, Karlsbad) grew up around a set of naturally hot mineral springs that have drawn visitors for spa treatment since the 18th century — among them, at various points, Goethe, Beethoven and a long list of European nobility. The town's architecture reflects that history: grand, pastel-coloured belle-époque hotels and elegant colonnades line the narrow river valley, giving it a completely different feel to Prague's Gothic centre.
What to actually do there
Walking the covered colonnades is the classic Karlovy Vary activity — several run along the river, each with its own mineral spring you can sample from a public tap. Locals and regular visitors carry a small spa cup with a built-in drinking spout specifically for this, sold all over town if you want the full experience rather than just watching.
The Grandhotel Pupp, the town's grandest hotel, is worth seeing even if you're not staying there — it's featured in several films, including a Bond movie, and its terrace café is a pleasant, if not cheap, place to sit. A cable car up to the Diana Lookout Tower gives a good overview of the valley and town below.
Becherovka
The town is also the home of Becherovka, a herbal liqueur made to a closely guarded recipe since the early 19th century, often served as a digestif or mixed into a simple cocktail locally. A small museum and shop near the centre tells the story if you want more than just a taste.
Getting there and timing
Direct buses run regularly from Prague, typically taking around two hours. The film festival in early July brings a very different, much busier atmosphere than the rest of the year — worth seeking out if that's your thing, and worth avoiding if you want the quiet spa-town version of Karlovy Vary.