There's a lady - an earl's daughter; she is proud and she is noble;
And she treads the crimson carpet, and she breathes the perfumed air;
And a kingly blood sends glances up her princely eye to trouble,
And the shadow of a monarch's crown, is softened in her hair.
She has halls and she has castles, and the resonant steam-eagles
Follow far on the directing of her floating dove-like hand -
With a thundrous vapour trailing, underneath the starry vigils,
So to mark upon the blasted heaven, the measure of her land.
- Elizabeth Barrett, 'Lady Geraldine's Courtship' (1844)
The borders of her land are marked upon the blasted heaven in thundrous vapour by steam-eagles. Don't tell me you can't get a hex out of that.
This hex is the domain of Lady Geraldine (or Lady Shahnoza, if it's in a Central Asian context), an impeccably bred and languidly bored young noblewoman whose power is maintained by her ownership of a flight of steam-eagles: flying steam-powered automata passed down to her from her distant ancestors. They maintain a continuous patrol of her borders, roaring through the air in a rumble of smoke and steam, and leaving long vapour trails in the sky behind them. Anyone who intrudes upon her territories without an appointment will be set upon by giant robot eagles and driven back beyond the borders. The eagles will initially just scream and threaten, but if defied or resisted they will escalate rapidly to the use of lethal force. Each eagle has a 20' wingspan, and their steel beaks and talons are very sharp.
Protected from the outside world by the sleepless vigilance of her automata, Lady Geraldine spends most of her time lounging around and waiting for something interesting to happen. She has seven official residences - four halls and three castles - each set in an elaborately landscaped estate; one is in a forest, one is by a lake, one is on a hilltop, and so on. Every few weeks she gets bored of the one she's living in and decides to move to another: she travels on the back of her personal steam-eagle (which she rides expertly), and is followed over the next several days by a baggage train of servants on horseback and on foot, bringing with them the extensive range of luxury goods which her aristocratic existence requires. The people of the surrounding area are taxed heavily in coin and coal for the privilege of her protection; they are deeply divided on whether the guardianship of the steam-eagles is worth the price demanded of them, but the question is ultimately moot, as the eagles won't let them leave. Only specially-appointed merchants are permitted to travel in and out of Lady Geraldine's domains, and they must keep rigorously to their assigned timetables in order to avoid an unfortunate run-in with their giant metal protectors.
Lady Geraldine herself is not a particularly cruel or evil person, but she's never known a time when she didn't have an army of steam-powered murder-birds waiting to kill anyone she points at, and this fact has rather warped her personality. She has an extremely high opinion of her own superior worth; she is not accustomed to being defied or disagreed with, and she takes criticism or rejection very badly. At the same time, however, a lifetime of never being challenged has left her a prey to ennui. The safe way to visit her domain is to apply well in advance, pay whatever toll she demands of you, keep your heads down, and agree with everything she says. More ambitious visitors could potentially earn lavish rewards by bringing her new ideas and experiences, things that might relieve her boredom and give her something more stimulating to do than just fret over the proper matching of perfumes and carpets; but any such novelties will need to be introduced with extraordinary tact, and without any hint of criticism of her current lifestyle or beliefs. Lady Geraldine's rooms have very large windows, and the steam-eagles are always perched just outside them, waiting for her order to strike.