'Rock City, IL' definitions:

Rock City, IL -- U.S. village in Illinois

From: Gazetteer 2000
Name :
Rock City, IL -- U.S. village in Illinois
Population (2000) :
313
Housing Units (2000) :
122
Land area (2000) :
0.142548 sq. miles (0.369198 sq. km)
Water area (2000) :
0.000000 sq. miles (0.000000 sq. km)
Total area (2000) :
0.142548 sq. miles (0.369198 sq. km)
FIPS code :
64837
Located within :
Illinois (IL), FIPS 17
Location :
42.412685 N, 89.468058 W
ZIP Codes (1990) :
61070
Note :
some ZIP codes may be omitted esp. for suburbs.