Twitter/@nxyxm

We'll get straight to the point with this one - is it a beach or a car door?

This is the latest optical illusion doing the rounds on social media and it's left people scratching their heads.

Some people are convinced it's a beach at night with rocks in the sea and stars in the sky.

But actually it's the bottom of a car door which is broken and needs fixing!

It isn't the first time that a mind-bending puzzle like this has caused a stir online though.

Remember the dress? Some people saw it as gold and white, while others were certain it was blue and black.

Check out some other examples below.

Is the diamond in the video moving when you watch it?

If your answer is yes, then think again. It might appear as if the diamond is following the instructions on screen, but it's actually completely still.

The image and video was made by researchers Oliver Flynn and Arthur Shapiro from the American University in Washington DC.

They used a series of flashing lights behind the diamond to trick the brain. When you watch the video, the flashes confuse the brain into thinking the shape is moving up, down, left and right.

Robert Maguire/Twitter

Another picture that has caused debate on the internet, especially for animal lovers!

Do you think the snap above is of a crow standing on a tiled floor wondering why it's being photographed?

Or maybe it's a black cat instead?

Make your mind up before we reveal the answer below. (Click here if you can't see where to have your say!)

It is actually a cat looking up at the camera, with one ear poking out which is probably why thousands of people online got confused.

Yurii Perepadia

This image was created by a designer called Yurii Perepadia from the Ukraine.

It was shared on social media by a neuroscientist Alice Proverbio whose job is to look at how the brain works.

What do think of the picture?

Alice says that the image is static but the way it is created tricks your mind into thinking it is moving.

She was using it to demonstrate how our mind works.

Twitter/@rebeccareilly_

Do you remember the photo that was shared on social media by a woman, who wrote: "Is this a door or a beach???"

And the internet answered with almost 20,000 people leaving comments with their best guess.

@ rebeccareilly__

Despite the big reveal some people on Twitter were still completely convinced it's a door.

One Twitter user called penquinn wrote: "Still looks like a door with holes in it to me."

Others have even been doing some photo editing themselves to show what the 'door' would look like with some added extras.

This dress caused a sensation online in 2015.

When looking at a photo of it, some people see it as gold and white, while others see it as blue and black.

Colours can appear different depending on what kind of light they're in. Something that's blue, for example, can look totally different in sunlight than under streetlights at night time.

But even when it's the same photograph, some people see blue, while others see white.

This optical illusion picture of a cat had lots of people online asking if the cat was moving up or down the stairs.

Because of the way the light falls on the stairs, there aren't many other clues in the picture to help the brain decide whether it's going up or down.

But one clue could be in the moggy's tail...

Tiziana Vergari

How many girls do you see?

This image which was posted to social media has left people baffled. It was posted with the caption "same but different".

People find it really hard to tell how many girls are actually featured in the picture.

When asked about the photo, the person who shared it would only say that they have two daughters.

This video of a father shuffling around his son's toy train tracks confused the internet.

Can you figure out what caused the optical illusion?

It was posted on Twitter and was shared thousands of times.

The track on the bottom appears to be much longer than the one on the top, but when one is placed on top of the other, it's clear that they are in fact the same size.