Old Town, Dubrovnik: Iconic for a reason
Lubenicka Loza, Cres: Tiny outdoor bar in a tiny old town on a cliffside. Terrible food, mediocre drinks, stunning vibes and views (esp at sunset)
Diocletian’s Cellars, Split: Incredibly well preserved basement of the old palace
Roman Amphitheater, Pula: A mini Roman Colosseum in better shape that still hosts events and has an accessible underground