Rivets are a presently unexplained phenomena native to the world of Cross. A Rivet is a small, fixed, area that has a specificaly set 'Weather' that cannot be either altered or pumped out in any yet known fashion. Rivets typically range in size from that of a small closet, to that of a small house and universally contain a large nondescript bronze plate. Magical and otherwise tests have yet to find anything metaphysically special about these bronze plates, what is known is that when they are removed from their Rivet, the Rivet loses its effect until its plate is returned. Each Rivet has its own unique Weather, that can be just about anything and as stated is independant of the weather around it.
The bizarre nature of Rivets have left a wide variety of opinions on their origin and effect on their surroundings, including but not limited to:
They should be studied for their potential applications, and harmful ones removed.
A Cult of the Plate that believes they are sacred relics, that hold the world of Cross together and keep it from being sucked out into the fog.
They are a joke/prank left by aliens, angels or some other kind of being.
An old possibly immortal man theorized they are the result of leaving bronze plates in the ground for extended periods, many many many years later, his results are inconclusive but he's still optimistic.