Water flows out from between thick slabs of rough cut stone stacked about four feet high. The construction bears a certain resemblance to a "dry" wall (a fieldstone wall without benefit of mortar).
Google's road map shows the traffic rotary, but the sat image has not caught up. The Bing Bird's Eye View is up to date.
I enjoy this little park; it provides a good point from which to observe how the locals negotiate the traffic circle. Despite the fact that most Vermonters don't seem to understand the concept at all (this being the first large scale circle in the state), traffic does manage to move more freely than when it was a traditional intersection with traffic lights.