city hall

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The building housing the administrative offices of a municipal government.
• noun The municipal government, especially its officials considered as a group.
• noun Slang An entrenched and insensitive bureaucracy, especially of a city.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun The building that houses a city's government.
• noun figuratively The city government; government in general.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a building that houses administrative offices of a municipal government