Boy's Surface represents an immersion of the real projective plane in the three-dimensional real space. It was constructed by Werner Boy in 1901. There is a whole web page on this interesting surface. In front of the mathematics research institut in Oberwolfach, Germany, you can see a model of this surface.
All images are created by Oliver Labs using the software surf written by Stephan Endrass and others.
Here is the surf source code of the image above.
Oliver Labs: my homepage: OliverLabs.net, my e-mail: suse TheAtSymbol OliverLabs.net