From the observatory website:
Weekend Observatory Guided Tours
Time: 10 a.m. - 4 p.m.
Date: Saturday and Sunday, February - December;
Year-round by appointment
Location: Blue Hill Observatory
A new Sunday tour option "BHO in Depth" is now available. At 10:30, 11:30, 12:45, 2:00 and 3:00 you can enjoy a 45-60 minute detailed tour with lots of time for questions and answers that includes parts of the Observatory the "BHO Overview" tour does not cover. The cost is $8.00 adults, $5.00 for ages 5-17 and BHOSC members of any age.
The Observatory is open to the public for 15-20 minute "BHO Overview" tours from February to December on most weekends from late morning to mid-afternoon as weather permits. These tours give a quick review of the work we do and the Observatory's fascinating history. The cost is $4 for adults, $2 for ages 5-17, free for children under 5, and free for members of the Observatory. A discounted adult tour admission of $3 is available for members of AMC, WGBH, Mass Audubon, AKA, KONE, senior citizens and students with a valid ID. Tours on other days and times are available by appointment. Tours last about 20 minutes and are adapted as appropriate for each group. For scouts and other groups larger than six, please reserve a specific time and program by calling 617-696-0562. You may also call to confirm availability before coming during the winter months. Educational programs are available 7 days a week through the entire year. More information can be found here.
The summit of Great Blue Hill can be reached by hiking or biking from the Trailside Museum and Blue Hill Ski Area parking lots on Route 138. Directions to the Observatory can be foundhere. Join us to learn about meteorology, weather instruments, the history of the oldest continually operating weather Observatory, or just to enjoy the beautiful, panoramic view from one of the highest points in eastern Massachusetts!