Monadnock. Part of my family lore. Been up it a few times, including once when it was so cold and windy at the top we huddled in the shelter of rocks. I always knew there was also Pack Monadnock to the east, about 1000' lower.
I discovered and climbed Pack Monadnock on a poorly mapped out day ride in 1977. Rode from Boston NW to just west of Nashua, then west on 101 over the hills and to Peterborough. As I neared 101's summit, I passed the auto road up Pack Monadnock. "So that it!" Turned around and rode up. On the gears I rode in those days, 42-19! It is a hard climb. No breaks and all well over 10%. Too steep to be any fun coming down but you can just descend west down 101 for one of the grand descents anywhere. Scary fast! For miles. (I rode into Peterborough where I had cousins, then south to Rt 119 in Mass and back to Boston. Got to miss going back up.)
175 miles and a glorious ride!
Ben