I parked at the small parking lot at the end of Long Pond Road and hiked the first relatively flat 1/4 mile along the shore of Long Pond. At that point the Perpendicular Trail formally starts. It's appropriately named, given that it climbs 1,000 feet in elevation in one mile, up a series of stone stairs and a section of rungs. The trail tops out at a false summit, an open rockface with great views of Somes Sound. After a quick snack break I continued to the actual summit, which is wooded with no views.
I descended down the steep Mansel Mountain trail to Gilley Field and then took a short connector trail to my car.
This was a great hike and an excellent workout.