After some hours of traveling, the group manages to find the old tower.  From the outside, it's a rather unimpressive building, only about twenty feet tall, with a circular outer wall about 15 feet in diameter, and a few large openings on the top floor for windows.  Based on the foliage surrounding it, it's likely been abandoned for a few months, but it should at least give some shelter, though likely rather cramped.  The front door is shut, but if anyone tries to open it, they would find it completely unlocked.