UNESCO describes New Caledonia’s series of lagoons as “an outstanding example of high diversity coral reef ecosystems.” You can explore this World Heritage Site’s watery wonders when Holland America Line cruises to the archipelago’s capital, Noumea. Plenty of other South Pacific adventures await, as well — from kayak trips on the Dumbea River and treks through Mount Koghi’s rainforest to encounters with the indigenous Kanak culture and rare cagou bird, the unofficial symbol of New Caledonia.