This basalt sea-cliff on the island of Heimaey in Southern Iceland looks just like a giant elephant or wooly mammoth dipping its trunk into the sea.
Heimaey is the largest island in the Vestmannaeyjar archipelago, which is a geologically young set of islands formed by volcanoes. Eldfell, a volcano on Heimaey, erupted in 1973, prompting locals to pump cold seawater onto the resulting lava flows in a successful attempt to redirect it from their harbor. The elephant on this island’s coast that attracts visitors is also formed from the volcanic basalt found everywhere on this island. Source: BoredPanda

This great photo by Dennis Hodges gives an illusionary look at the buildings of Manhattan. It takes a short while to get your head around the perspective but eventually it can be seen correctly.

Look at this beautiful lake. You might be surprised to find out that there is no water in this picture at all. What looks like a lake is in fact a white garden wall. Image source unknown

If you are an optical spy regular you’ll be aware of our love of illusions. We have produced quite a few of our own over the years and thought you might like to see the one voted as 'the greatest optical illusion in the world', ‘The Steelwork Illusion’. As ever our inspiration comes from M.C. Escher‘s work around the ‘Penrose Triangle’. If you can't see what's going on take a closer look at the girders the third worker from the left is laying on, then follow around the joints  of the metalwork or check out the detail below. Original image source unknown

We found these great, well timed photos, on the internet giving the illusion of the sun going through a hoop. We loved it so much we decided to animate it. What do you think? Original image source unknown.

Original image above credit Kimery Davis modified below by Optical Spy