1. Cloudbusting

Look up! The sky is full of strange sights – from phantom faces to flying saucers.

2. What goes up…

Nothing beats gravity, right? Wrong. There’s a magic road in North Korea where things roll uphill!

3. Bird’s eye view

Who is this seen high above Canada’s Alberta Badlands? And why is he wearing an earring?

4. Seeing 3-D

Argh! Don’t look down! Without leaving the earth, here’s how one artist can make you feel you are about to fall into it.

5. H²Optical

And here’s how another can put you underwater. Without getting wet.

6. Take a trip

If you stare long and hard enough, the walls might start melting.

7. Are you colour-blind?

A very famous recent illusion that we still can’t resist. It’s black and blue! No, it’s white and gold! The dress with a double identity.

8. Somebody’s following you

Don’t worry, it’s just a dinosaur.

9. The wonderland room

One minute you’re tall, next you’re small. The weird space invented by an eye doctor.

10. Turn, turn, turn

Round and round she goes, which way she’s spinning, nobody knows.

11.

Can’t see number 11? Must be another optical illusion!