They look like the entrance to Hell!
7. Surreal spiderwebs: Fleeing torrential floodwaters near Wagga Wagga, Australia, thousands of spiders cover fields with cobwebs.
13. The Sardine Run: occurs from May through July when billions of sardines move north along the east coast of South Africa. Their sheer numbers create a feeding frenzy along the coastline.
14. The Giant’s Causeway, Northern Ireland: an area of about 40,000 interlocking basalt columns, the result of an ancient volcanic eruption.
15. Sailing stones in Death Valley, USA: a geological phenomenon where rocks move and inscribe long tracks along a smooth valley floor without human or animal intervention.
16. Tidal bores on the Amazon in Brazil and the Severn in England: a tidal phenomenon in which the leading edge of the incoming tide forms a wave of water that travels up a river against the flow.
18. Circumhorizontal arcs, misleadingly known as fire rainbows: an optical phenomenon featuring an ice halo formed by plate-shaped ice crystals in high level cirrus clouds.
22. Undulatus asperatus aka “roughened or agitated waves”: This cloud formation has been proposed as a separate cloud classification by the founder of the Cloud Appreciation Society and would be the first new type of cloud recognised since 1951.
The light pillar looks like a thin column that extends vertically above the source of light. They have been known to produce false UFO reports.
28. Rainbow eucalyptus aka rainbow gum: patches of outer bark are shed annually at different times, darkening and maturing to give blue, purple, orange and then maroon tones.
Special mention: The Moskstraumen is a tidal whirlpool, one of the strongest in the world, that forms in the Norwegian Sea*.
*Note: This may not actually be a picture of the Moskstraumen— they’re difficult to take! If you have one, please post in the comments below!
An earlier version of this post did not properly cite the source of information relating to Monarch butterfly migrations.