One of the hardest hills I've ever climbed. It took me three attempts to be able to do it without stopping. It starts with a quick steep section, you turn around a curve and then you see it: a wall, straight as an arrow that goes on for almost a mile. Climbing it, once you get the hang of it, it feels like two immense sections of 25-20% punctuated by a shorter section at around 10-12%, that feels easy compared to the stuff at either side of it. After the top hard section, there's a bit of a dip, followed by a spike of close to 30% right at the top, but you have some momentum going into it, so that's not so hard. The pavement is in pretty bad shape and there are drainage bars paved across at regular intervals, so the descent is frightening. The road is technically on private property with no-trespassing signs, but hikers use the road all the time, and there's no real sign that anyone would ever tell you to leave.
Mount Tom is located in Massachusetts. It is 1545.7 meters long with an average gradient of 14.2% and a maximum gradient of 23.6%. Find similar hills.