Bulldozers began taking apart some of the gates and tracks at the Melrose Park site.
The amusement park closed last fall.
Costco bought the land at first and north in Melrose Park and expects to open a store by November.
Six Flags Great America in Gurnee bought one of Kiddieland's most popular rides - the "Little Dipper" roller coaster. It is now set up in the Six Flags park.