This 1200m-long cave system, located some 16m (and 45 steps) under the Castle District, contains a motley collection of displays in its joined-up labyrinths encompassing 10 halls. Expect the history of Dracula (supposedly imprisoned here), dry-ice mist and and a ghostly masked ball, with music carrying eerily underground. It’s all good fun and a relief from the heat on a hot summer’s day – it’s always 20°C down here. Tour by lamplight after 6pm. There are two entrances.