They should find;
1) Sites of the last remnants, be it them standing against the end, trying to stop the apocalypse, fighting each other or trying to rebuild. All dead, all mummified by the sheer magical energies present and on occasion hordes of undead citizenry and guards, bearing weapons and tools.
2) Sites of intense magical energy, like a lake. Dangerous to remain (debuffs and monsters) in but instantly refilling their mana.
3) Fallen adventurers, be it those who fell to the hordes of the dead, to the foul magic energies or to more mundane threats like betrayal.
4) Travelling magical storms, mobiles spells fed by the present magical energies. Be it a rain-cloud dropping shards of ice, lightning strikes, beams of light and anything else.
5) Foul creatures, twisted by the maleficent, the mad, the disaster and it's fallout. Some dangerous and others merely wretches from their exposure to the wastes.
6) Places trapped eternally in the day of the disaster or after it, living through it again and again no matter what the players do. They can talk to the people in it, interact with them but it must always end as it started; with them as corpses.
7) The broken guard; the golems they set to preserve order, to maintain the checkpoints, to fight the end. They failed yet some still stand, guarding their posts, keeping all back by whatever means needed. They come in many forms, from possessed suits of armour to statues and even busts that launch forth spells.
8) The survivors; insane, lucky or dammed by god to live in such a hellish place, they might help or attack any outsiders. Never found in large groups, out of fear of being detected by the many threats of the wastes.
Though usually not too dangerous it should be noted they can pass the broken's checkpoints because they are the children of the citizens. They even on occasion can direct them and wield the old weapons, weapons far beyond mere swords or bows.