Calais Observatory

Calais Observatory is an astronomical observation site in Meridian Park containing two granite structures including a transit stone and an eight-foot-tall clock stone designed to hold telescopes and other instruments. These stone pillars and an accompanying NOAA marker remain visible today as evidence of the facility's original scientific purpose.

The site was established in the mid-1800s as part of the United States Coast Survey effort to determine accurate longitude measurements for precise mapping. In 1866 this location was precisely fixed through astronomical observations, making it one of the most accurately positioned places in the nation at that time.

The site represented early American scientific advancement, contributing to national efforts in astronomical observations and geographical coordinate determination across New England.

The site sits within Meridian Park and is accessible during daylight hours with the granite structures serving as clear markers. Taking time to examine the stones and read the NOAA plaque helps visitors understand the scientific work that once took place here.

In 1866 this location became one of the most precisely surveyed places in America and served as a reference point for mapping the entire northern coastal region. This exceptional accuracy made it a foundational anchor point for all subsequent surveys in the area.

Location: Calais

GPS coordinates: 45.18480,-67.28080

Latest update: December 14, 2025 18:16