CHICAGO (CBS) — This fall, it will be playtime for sea creatures along the lakeshore in Lake County.

Up at the Fort Sheridan Forest Preserve in Lake Forest, fish and other creatures will benefit from a new underwater playground. Between now and October, man-made underwater reefs will be created along a mile and a half of the lakeshore.

Materials will include limestone slabs, tree trunks with branches and roots attached, cobblestones and sand. The reefs will also stabilize the shoreline and help prevent erosion.

The project is a joint effort of Lake County Forest Preserves and the U.S. Army Corps of Engineers.