Lake Denoon is a 162-acre lake in the southwestern portion of the City and is also partially located in the Town of Norway.  The lake has a glacially formed kettle basin that reaches a maximum depth of 55 feet with bottom substrates varying from sands and gravel to muck.  An outlet stream on the south end drains to Ke-Nong-Go-Mong (Long) Lake in Racine County.  A cattail island and an extent of cattail shoreline are found on the lake's west end.  The remaining lakeshore is mostly developed with residential housing.

Denoon Park, located on the northwestern shore of Lake Denoon provides lake launching access.  Wetlands and woodlands within the primary environmental corridor associated with Lake Denoon are also found in the park.  Lake Denoon provides habitat for tha Black Tern, a rare bird species.

Lake Denoon Advancement Association is a volunteer organization of Lake Denoon residents who conduct projects to manage, protect, and enhance the lake.