One of only six such facilities in the world, the Gaithersburg International Latitude Observatory played a vital role in early 20th-century efforts to measure the Earth’s wobble on its axis. Today, visitors can explore the site and learn about the city’s surprising connection to global science and astronomy.

About Heritage Days

Heritage Days kicks off this weekend, June 28 and 29! Now in its 26th year, this free, family-friendly festival invites you to explore 33 historic, cultural, and outdoor sites across Montgomery County, many of which are open specially for the event.
To help plan your visit, the official 2025 brochure and map are available at participating sites and on the Heritage Montgomery website. See the list of participating sites below to plan your visit to the Heritage Area. Enjoy live music, exhibits, guided tours, and hands-on activities that bring the county’s rich history and diverse heritage to life.