This is a map of Venus. Click on image for full size version (170K GIF) Image from: NASA

Tessera is a unique feature of Venus, and is also known as "complex ridged terrain". These features are found on some of the Venus Plateau Highlands.

Tessera is created is by a shortening of the crust. That is, when the crust is pushed together, the surface folds, buckles, and breaks. This process may be related to the process of mountain-building on Earth. But, because Venus does not have continental drift, the process must occur somewhat differently. Nevertheless, tessera provide evidence that the surface of Venus may be in motion.