These are WONDERFUL locations and hooks for high level play, and even if you don't like using giants as monsters, the majority of them can use any kinds of monsters to populate them. They would all fit so well into my campaign setting.
My setting is a new world that manifested in the Material Plane only a couple hundred years ago, crafted in the Worldforge of the Elemental Planes by giants, genie-kind, elementals, and celestials, to become a new home for displaced survivors of mortal civilizations, after their old worlds (a scattering of long forgotten realms) were annihilated by the Elder Elemental Evil of Destruction (guess who).
We get to play with exploring a world that needs discovered and tamed. The architects created "foundations" of fantasical locations, buildings, and cities throughout the world for mortals to explore for claiming and settling. There are always cooler, larger than life aspects to these places and the settlers may not even know all the secrets of their new homes. They also created and sometimes populated dungeons that house secrets and magics for mortals to discover when they have the power to find and claim them. Between those two themes, it's like a scavenger hunt of wonder to collect knowledge, magic, wealth, and bastions for settling.
It's very primal, with elemental nodes bringing elemental energy to the world, flying earthmotes, newer mortal realms vying for prominence, or at least a place in the world, a hidden hollow world, and so many secrets to uncover.
As a DM, I am stoked for this product! It really fits my needs!