Beaver's Dam, which eventually became known throughout Narnian history with the spelling of Beaversdam, was a historically significant location in the Duchy of Lantern Waste in the northwestern Kingdom of Narnia.
Beaver's Dam was originally the home of Mr. and Mrs. Beaver, who aided the Pevensies in fleeing from the Witch's Secret Police. Their abode actually became the first base for the Narnians against Queen Jadis before the unification of Aslan's Army at Aslan's Camp, at the start of the Winter Revolution.
It was often used as a landmark on the Great River, and because of its historical meaningfulness throughout the land, it became a popular destination and, eventually, a populous community of Old Narnian talking beasts.
During the then-nascent Telmarine Conquest, the Old Narnians were exiled from the community, as Telmarines occupied the area and developed the community into a town of humans. It would eventually become the Telmarines' new capital of Narnia, with the Castle of Caspian soon in construction on the western bank of the Great River. The human-only immigrants gave Beaversdam its new spelling, and developed it into a small thriving city. The two brothers of Beaversdam, loyal to Caspian IX, were shut up as madmen by Miraz.