In winter the lake is used for ice skating, while in summer you can swim here or enjoy nice beaches. Good option for the city center, right?
Anchorage Park Foundation Website http://www.anchorageparkfoundation.org/directory/gooselake.htm
Address Goose Lake Park, Anchorage, AK 99508, USA
Coordinates 61°11'48.563" N -149°49'11.223" E