Portland Observatory

Also known as: Observatory
138 Congress St., Portland, Maine


Historic American Buildings Survey Allen L. Hubbard, Photographer March 23, 1936 GENERAL VIEW EXTERIOR (WEST ELEVATION)

Photo taken for the Historic American Buildings Survey


Street View 


The Portland Observatory is the only known surviving example of a maritime signaling station. Maritime signaling stations were once prominent fixtures along the coast and in important port towns relaying messages from ship to shore. Visual communication between ship and shore meant that merchants and ship owners could both receive and send messages to their vessels several hours before the vessel reached port. Consequently, owners could learn of problems the vessel might have encountered on its travel such as damaged cargo. This method of communication also enabled a ship owner to redirect his vessel to another port if the cargo had been sold or to reserve a berth on the wharves and hire a crew of stevedores to unload and reload the vessel in a timely fashion. -- National Historic Landmark statement of significance, February 17, 2006

National Register information 

Posted to the National Register of Historic Places on April 24, 1973
Reference number
Areas of significance
Community Planning and Development; Architecture; Communications
Levels of significance
Local; National
Evaluation criteria
A - Event; C - Design/Construction
Property type
Historic functions
Water-related; Outdoor recreation; Communications facility
Current functions
Museum; Water-related
Period of significance
Significant year

Update Log 

  • November 29, 2016: New Street View added by Brian Bartlett
  • October 6, 2015: Photo imported by Brian Bartlett
  • August 23, 2013: Photo imported by Brian Bartlett
  • May 17, 2012: Imported photo from HABS/HAER