Stone Wall Fountains What Is The Primitive Circular Stone Structure In Front Of The Washington DC Capitol Building Called?

What is the primitive circular stone structure in front of the Washington DC capitol building called? - stone wall fountains

When I was young, my family went to Washington DC, and there was a structure, in particular, have tried to obtain data and photographs, if I forget the name.

It is a stone benches along the wall and a wrought iron gate, but has no roof, and seems to be quite old. It may have been a source located in the center, but not sure. Perhaps a monument to the class, not quite sure either.

I have the address of the Capitol, they have lived, but seems to be in a park.