Visit the Mapu'a 'a Vaea blowholes

The highest tides on Earth, best watched among the Hopewell Rocks flowerpot stacks.

Waves forced through lava tubes blast spray 30 metres into the air — locals throw coconuts in to launch them.

Sandy spit at Denmark’s northern tip where the Skagerrak and Kattegat collide.

One of the few waterfalls on Earth that pours straight into the ocean.

Fog-bound desert shore of shipwrecks, seal colonies and dunes dropping into the Atlantic.

Tonga is one of the few places you can legally swim with humpbacks, which come to Vava’u to calve from July to October.

Witness ocean waters glowing at night due to bioluminescent plankton.

The "river of five colours", turned red by aquatic plants between June and November.