Stuck dramatically to the edge of a cliff since 1910, the world-renowned Musée Océanographique de Monaco, founded by Prince Albert I (1848–1922), is a stunner. Its centrepiece is its aquarium with a 6m-deep lagoon where sharks and marine predators are separated from colourful tropical fishes by a coral reef. Upstairs, two huge colonnaded rooms retrace the history of oceanography and marine biology (and Prince Albert’s contribution to the field) through photographs, old equipment, numerous specimens and interactive displays.

In all, there are around 90 tanks in the aquarium containing a dazzling 450 Mediterranean and tropical species, sustained by 250,000L of freshly pumped sea water per day. School holidays usher in free hourly light shows in the Salle de la Bileine (Skeleton Room) and feel-the-fish sessions in the kid-friendly tactile basin (45 minutes, €5); tickets for the latter are sold at the entrance.

Don't miss the sweeping views of Monaco and the Med from the rooftop terrace and café.