Abandoned Bastion

Publisher's blurb:

The path leads through a forest, past a lake and to the foot of a large cliff where a small opening can be found with stone stairs carved into it. The winding stairs seem to go on forever but, finally you arrive in the old abandoned hold.

There are multiple rooms and then two sets of stairs that lead deeper into the compound. The stairs take you to a large open cavern and a bridge that leads over to more stairs that continues to climb up through the mountain. At the top of the stairs across a natural bridge lies the bastion.