These are some children having fun in Rings Fountain, part of the Rose Fitzgerald Kennedy Greenway, which, as part of the Big Dig project, replaced a truly hideous elevated freeway that sliced through the heart of Boston.
This is part of the Greenway know as the Great Room, which has at its core a "lighted, choreographed fountain shooting 30 to 40 feet in the air designed by Wet Design. The 64 nozzles are set in three circles of rose-colored stone inlaid at surface level. Since each nozzle works independently, there are innumerable design configurations possible with the jets of spray. The fountain is air powered vs. water-pressure powered, so the result is a light spray." More info available here in this PDF.
Taken as part of the one-year anniversary photowalk of the Boston, Massachusetts, Flickr group. (Thanks to Greg for organizing this!)
I really love the details brought out by the light reflected in the water. Kind of a cool effect, I think.