Tropical plants you’ve only ever read about can be spotted in all their glory at this spectacular botanic garden, which took root in 1850. Among its rarest specimens are the Hawaiian loulu palm and the East African Gigasiphon macrosiphon, both thought to be extinct in the wild. Several of the towering trees are the largest of their kind in the USA. The self-guided tour is excellent and gives an introduction to plants and trees found across Hawaii.

　　Oddities include the cannonball tree, the sausage tree, and the double coconut palm capable of producing a 50lb nut – watch your head! Follow your nose past fragrant vanilla vines and cinnamon trees in the spice and herb gardens, then pick your way among the poisonous and dye plants. Don’t miss the blooming orchids or the elegant – and appropriately named – royal palms. The gardens are on the National Register of Historic Places. The free guided tours are expertly led and engaging. Call to reserve a spot.