1.

a stream of water that is forced up into the air through a small hole, especially for decorative effect, or the structure in a lake or pool from which this flows

2.

In this case the fountain cointain not water but a social space in which people can go, refresh and interact

3 (txt).
fountain: The fountains in south central Park park are refreshing showers in the summer, and playgrounds for the children. try it, take a shower if its hot

4.