Whether they're optical illusions, photo trickery or just perfectly timed, all of these photos will make you stop and ask "what's going on here?!"

1. How's this for some landscaping?

2. Boating, or floating?

3. Perfect timing, or something even better

4. I'm convinced he has a magic camera

5. Nothing in this photo is red...yes, really

6. The grey bar in this photo is one solid color

7. Is this chair facing forward, or backwards?

See for yourself:

8. Remember this tricky image? How many legs does the girl have?

If you thought that was confusing, just wait until you see the rest of the list!

9. They grow up so fast

10. I can't even explain this one

11. There's only one car in this photo

12. Slow boat to heaven?

It's actually San Francisco's Sutro Tower, which has 3 radio masts on top.

There are even more confusing photos at the end of this list.

13. Does this girl have a stretchy arm?

14. Make room for this puzzle...

Six girls sitting on a couch. But look closer at the 3rd girl from the left. Where are her legs?

Give up? They're there, the girl next to her is the one who's actually squished onto the couch.

15. When your carpenter is also a magician...

16. This boat is completely flat

17. This one is just plain old optical trickery

18. Who are you going to believe, this illusion or your lying eyes?

19. "Glued in Firenze"

How do these two manage to float on the ceiling? Look at the bottom of the photo if you need help figuring it out...

20. This is the strangest one of all...

So what's the deal? This is a "forced perspective" shot. The men in the cherry-picker are high off the ground, but the crane is extended at an angle, so it looks like they're only a few feet high.

That's what makes it seem like they're both high up working on the overpass and very close to the person on the ground.

Share these strange and challenging photos with someone you know!