Keltoi are very cultured and sophisticated people. Yet much of their culture and achievements were either mis-credited to the Romans, or the Romans wiped them out through genocide. Here I'd like to discuss the wonderful achievements and cultural relics the Non-Romans have achieved. For example: the Aquaduct.

I'll kick off with some stuff about the Keltoi:

A Celtic town has been discovered in Southern Germany between Stuttgart and Ulm. It's walls surround an area of 6 square miles - 4 times that of the Aventine wall of Rome.
Another example is the large Celtic city of Manching, the capital of the Vindelici. It had walls 5 miles in circumference. It was burnt and looted by Romans in 15 BC.
Celtic cities were far from silly huts with straw thatched on the roofs. One clear example of their expertise was the crannog, a timber-framed circular house, built on an artificial island in the middle of a lake or bog. Boulders were sunk and used as foundation, in combination with timbers. The houses would be up to 50 ft in diameter.