The Chomphet Pagoda (Phra That Chomphet) stands on its own on the central peak of the ridge of Khao Wang. The elegantly slender spire was built around the same time as the palace complex, but it reportedly was built over an older shrine. However, there's no information about that shrine.
Chomphet pagoda, as seen from the palace complex.
The pagoda sits on the highest of the three peaks, so you get excellent view from it of both the palace complex as well as Wat Phra Kaeo Noi. There are four entrances at the base, through which you can gain access to the center, and from there four more passages lead up to a walkway around the very base of the bell. These stairways are very low, such that I was practically on my hands by the time I exited the top.