3D drawings out of chalk are works of art that are 2 dimensional. And when they are drawn on the streets they provide an additional 3rd dimension that gives them an optical illusionary effect when viewed from a certain angle. A few such optically deceptive images are listed below.
This 3D optical illusion of Santa Claus receiving your special requests below the post box is done by chalk.
This illusion of the road caving in and a waterfall within the cave are drawn with chalk.
This illusion of a river flowing through the streets makes for a great photo shot like the three girls sitting on illusionary boats.
An illusionary picture showing the reflection of a church in a make believe water pond.
An illusionary artwork of a girl offering a little man sitting on the top of a bottle a glass of juice is amazing.
An illusionary couch at the airport with a girl sitting on it is creative.
A man tries to escape from prison in this illusionary picture.
The pool and some men sitting around it are all an optical illusion.