Voimios strap

The Voimios strap was discovered by Voimios, a mage from the Sorcerers' Collegium of Videssos, during or shortly before the Time of Troubles. It was an object that had only one side, not two, in contravention of all common laws of physics. During the Makuraner invasion, Videssian mages concealed a canal from the invaders by turning a canal into something resembling a Voimios strap.

Literary comment
The Voimios strap is based on the Möbius strip, also spelled Moebius strip.