The logical place to work through the Becherovka catalogue, this bar in the spa district serves the liqueur in its various forms: neat, on the rocks, and in cocktails including the local Beton (Becherovka and tonic). The Beton in particular is more refreshing than it sounds — the bitterness and herbal warmth work well with a good tonic, and it is far lower in sugar than most aperitivo-style drinks.
The bar is small and often busy in the evenings. Worth visiting even if you are uncertain about herbal liqueurs — the staff know the product and can talk you through the options without being pushy about it.