Lake In The Clouds

"And so all of the mysterious folk suddenly and mysteriously vanished," Professor Milltender intoned as he stood at a podium reading from his notes. "To this day no one knows how or why. Questions?"
As usual, none of his students raised a hand. Three were snoring in the back and a fourth had fallen out of his chair to drool on the floor as he slept.
"Class dismissed!" he called out. All thirty students jumped to their feet, grabbing up their slates, papers, and writing pouches as they rushed for the door. Incredibly, the three who had been snoring in the back were the first to make it out.
"Amazing," Headmaster Ridgewell said as he stepped in from the doorway connecting the lecture hall to Professor Milltender's study. "That was the best demonstration of the Hrokentorm Vanishing ever presented!"
Professor Milltender grumbled under his breath too softly for the headmaster to hear.

— a class at Larkspur Academy

LANDSCAPE
Lake of the Clouds is a beautiful lake surrounded by rolling hills covered with wild orchards which are themselves surrounded by overgrown pastures and fields. Farmsteads dot the lands. In the widest valley between the hills and touching the shores of the lake, is a a small town with a rugged keep at the center. Encircling the entire territory is a wall of blue-veined marble, the same stone used to make every building. This wall is vital as it marks the edge of the solid ground safe to stand on. Beyond the wall, is the ever shifting vapors of the great cloud that keeps Lake of the Clouds floating hundreds of feet above the ground. All the buildings were built for the Hrokentorm, a race that averaged eighteen feet tall. No one lives here now, except for the goats and chickens gone wild since the mysterious leaving of the Hrokentorm.
NEW INHABITANTS
Very young griffons survive after hatching by hunting the goats and chickens until they learn to fly, at which time they leave Lake of the Clouds in search of bigger, more filling, prey. Adult griffons have built great nests upon every rooftop and, once the female has laid her eggs, the male departs before she decides he is a threat to them. Once the eggs hatch, the female flies off, leaving the hatchlings to fend for themselves.
The Order of Argozi Knights ride the griffon they have bonded to since the griffon was a hatchling. Though they breed and raise griffons at their home castle of Skyloften , an earth-bound castle, finding new blood to keep their bloodlines strong is vital. The Argozi collect a few of the hatchlings every year from Lake in the Clouds and take them back to Skyloften to be added to the prides.
REBUILDING
Capturing hatchlings is the easy part. Being able to carry one back to Skyloften takes time as each one captured must then be tamed enough to be held on by the knight sitting on the back of an adult griffon. Always careful to have the least impact on the griffon nursery, the Argozi have renovated the half dozen ruined farmsteads nearest the outer wall as outposts and hatching training pens. One thing they quickly learned is why every building had a silver rod firmly planted in the ground and built to reach six feet above the peak of the roof. Clouds encounter alot of lightning as they drift through the skies, and the silver rods catch the lightning, keeping everything safe.
OTHER USES
The Argozi sometimes gather Hrokentorm things to sell to scholars, who pay well for things from the vanished giant empire. Few such things remain after the five thousand years or so since their vanishing. Giantkin nowadays tend to destroy anything of the empire they come across as a hated reminder of a time when they were harshly ruled over by the supreme giant race so what few things non-giants find are very important to the study of that age.
With the destruction of the Gateways turning the world into a place of conflicts and wars for resources and the commanding of trade routes, the Argozi had turned to planning how to turn Lake in the Clouds into a haven for themselves and their families without destroying the wild griffon nursery they so stoutly depend on.