Hidden Tower is the secretive formation northwest of Lady in the Bathtub. it's big, around 300 feet high and, like most of the Valley of the Gods towers, steep in every direction. In fact most facets overhang.
It's close to a two-mile (1.25-hour) hike from the road. Park just off the main road in a big wash (with blue-gray limestone slickrock) a half-mile north and east of the Lday in the Bathtub parking. Hike the wash northwest toward the tower. At the steep talus slopes the more westerly ridges are easier to ascend and dump you out at the southwest corner.