After about 1.5 mile you will reach Hillside street, at which
point you will have covered roughly one quarter of the hike.
Cross the street carefully and head for the Reservation Headquarters
on the right. You will be able to take a Reservation map there.
Follow the blue marks behind the buildings to continue the
hike on the Skyline Trail's northern branch. You will successively
ascend Hancock Hill, Hemenway Hill and Wolcott Hill before
you head for Great Blue Hill, at an altitude of 635 ft. You
will first see Eliot Tower, an observation tower from which
you will have a great view over the Boston skyline far away.
You can continue on the Skyline Trail for less than a quarter
mile to reach the observatory itself.