Later this month, I'll post an adaption of one of the Fifth Gate Challenge entries.
Until then, here is an expanded concept elevation of the 2015 Park castle:
The feel here is more along the lines of Fortress Explorations (also at the base of a mountain): a defensive, Scandinavian castle (inspired by Anna's) rather than an ornate, baroque chateau.
The "Boathouse" at left is where the flume boats re-enter the mountain. The Lighthouse Tower should be apparent.