Stand on the equator and date line in Kiribati

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

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

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

Drift by boat beneath a cave ceiling lit by thousands of glowworms.

Fly over the Nazca Lines, giant desert figures etched into Peru's coastal plain two thousand years ago

Swim at night in a lagoon near Falmouth where bioluminescent plankton light up every stroke.

Plankton light the surf electric blue on Vaadhoo and other islands on dark nights.

The "Eye of the Sahara" from the ground.