Julian Beever and his work of art at La défense - Paris (on the top of a tower it's me ;)
The author of this great drawing is a super creative person also known as Pavement Picasso whose real name is Julian Beever.
Not to reinvent the wheel I will cite Wikipedia: “Julian Beever is an English chalk artist who has been creating trompe-l’œil chalk drawings on pavement surfaces since the mid-1990s. His works are created using a projection called anamorphosis, and create the illusion of three dimensions when viewed from the correct angle.
Beever works as a freelance performance artist and creates murals for companies.” Keep in mind that every sidewalk drawing is entirely flat!