Colouring a Moebius strip
An exhibit of "Matematica viva", in Lisbon (Portugal) that shows that we need six colours to colour any map on the Moebius strip. The map in the photo has six regions, each of them is adjacent to the other five.
See also a virtual image.
The image belongs to the sections...:
Colouring a surface (Topology)
From the exhibition "Matemática viva", Lisbona, 2000 (Other exhibitions around the world)
The Moebius strip (Topology)