Mudflats and salt marshes don't sound as sexy as alpine peaks, but Denmark's west-coast national park demonstrates how appealing they can be, with tractor-bus rides to salty offshore islands, fat harbour seals lolling on sandbanks, and the chance to put on waders and pluck and shuck oysters. Plus birds – so many birds!
In the Wadden Sea National Park (in Danish, Nationalpark Vadehavet), the seabed meets the horizon twice daily, when low tide exposes tidal flats of sand and mud, and birds swoop to hoover up the buffet on offer (tasty morsels like worms, cockles, crabs, shrimp and snails). Annually, some 12 million feathered friends use this region as a feeding place, or to rest, on their migrations.
The history of humans in the region is also on show, with dikes and polders as evidence of the struggle to master the watery landscapes.