This cache is located in the Andover Village Improvement Society (AVIS) Peggy Keck Reservation - named after Peggy who was an influential leader at AVIS for many years and who was married to Jim Keck, a beloved Professor of Mechanical Engineering at MIT.
The reservation used to be called Rocky Hill for reasons that will become clear. The cache is hidden in one of the larger outcrops, a moderate cliff.
Approach the hide from below, not above. Rock climbing is NOT necessary, but you still need sure feet.
Added 4/6/20: I have adjusted theTerrain rating up to 4 because of the fallen tree in front of the cliff. I left the overall Difficulty at 3 - I made the hide easier to find once you get to the face. Hide is waist high, to the left (northish) of the tree, not on the ground, so don't go rooting dangerously around. Also gave a more detailed hint - if you get as far as the face, you should be rewarded!
Congratulations to Team Bullis on being FTF!!