The Fountain is a landmark located in both the town and in the City. It is not to be confused with the Wishing Well in Animal Crossing. Serena the chihuahua inhabits the town fountain, giving the player axe upgrades (golden or silver, or she'll give the player's regular axe back).
In Animal Crossing: City Folk
The fountain in the City is located near where Phineas and his balloon stand appears.
Players may throw in a regular Axe (almost broken or not) into the fountain and Serena will appear and ask the player what type of axe the player threw in. The result of the answers are completely random, and she may give the player a Silver or Gold Axe, or just give the player their axe back. Serena may even take the player's axe without anything in return if she isn't in a good mood. The fountain serves no other purpose than to give the player the axes, and is otherwise a mere decoration. On the first day the fountain is built, the player cannot throw in an axe because mayor Tortimer is blocking the way.The player cannot drink from it, which is noted by Tortimer on the day it is built.
Animal Crossing: New Leaf
A fountain appears in Animal Crossing: New Leaf as a Public Works Project. Is it available at the beginning of the game and costs 99,800 Bells to build. Unlike City Folk, this fountain only serves as a decoration. The size of the fountain is 3x3.