Complex sentence: A raceway pond is a long, relatively shallow open-pond made up of channels that wind around, sometimes in the pattern of an automotive raceway, though many ponds look like a very simple maze if looked at from above.
Split into simpler sentences: A raceway pond is a long, shallow open-pond made of channels that wind around. The name comes from their appearance, in the pattern of an automotive raceway, though many ponds look like a maze from above.