Realistic and 3D Art

So I'm doing this project about Realistic and 3D Art for school and I thought why not share some photos I found and post it on my blog for people to see. Oh! And none of the photos are mines so all credits go to the artists.

Here are some I'm going to use for my project.

 It's really hard to believe that this photo here on the right was drawn using a pencil, pen, etc.
If you hide the right side with your hand, you'll definitely think that the left side is a photo and not a drawing.

 Here's a realistic painting that was done on the ground. I really does look like two angels flying out of the sky which is under the ground...Sounds weird doesn't it. Though it only looks like that from a certain angle. If you look at the photo of the right, you see the exact same painting but from a different angle. Looks weird right?

 This one above is probably my favorite. Why? Well look at it. It's so damn realistic! It looks like the elevator floor has a hole in it!. I would be extremely scared if the elevator door opened and I saw that. I would be like the person on the left.

 There's a hole and a waterfall in the ground! Of course not, it's just a painting. I really well done one too. Though I wonder how they imagined this? How did the know how to paint this? Did they already paint it on a software the painted onto the ground? Or did they do it right out from the head? Well I guess I'll have to continue my research for these information.