With their heavy metal exteriors and tall legs, these 12 Arctic and Antarctic structures look surreal and almost sci-fi against the white polar landscape.

Armed to the gills with 32 razor-sharp teeth, the Goliath Tigerfish may be the most fearsome fish you'll ever see - just hope it doesn't see you first!

These 12 ancient ruins, archaeological digs and historic sites could be wiped off the face of the earth by climate change, war and other challenges.