- COORDINATES: 39.781182, -77.733582
- COUNTY: Franklin
- DISTANCE TO NEXT: Chambersburg - 11
- EXPLANATION OF NAME: Named for Greencastle In North of Ireland
- MANUFACTURER: Carlisle Foundry Company
- FOUNDED: 1750
- SHAPE: Standard 1-sided
- STATUS: This town, at the intersection of a U.S. numbered route and a PA numbered route, still has all four of these original markers. Few towns have more than one remaining.

Photo Sept 2011 by JGraham

January 2016 photo by Mike Wintermantel
US 11 at South Carlisle Street at south end of town