They are awarded 2464gp and a total of 29,993xp. That experience award is colossal in itself. There is only one thing that fits that shape without a discernable treasure: Rats. Epic numbers of Rats. (50) Normal Rats is 250xp, Treasure Type L. To equal 25,000xp alone there must be encountered (5,000) Normal Rats. Thats Maximum Normal Rats x 100. Thats also Treasure Type L x 100. Compared to this the (6) Ghouls, (24) Hobgoblins, and (60) Orcs are nothing. Now Imagine your PCs have headed out through the Wilderness and found this castle. There is a bridge out frm the high ground to a gate keep, and another gate keep beyond that, and then the actual castle in the distance. Ground level looks about fourty feet above the swamp. The bridge has a distinct odor. You cross but you cant go in the gate keep, not because its locked up but because the doors are off their hinges and you see lots of rats. There are five thousand rats here and you must slaughter your way through them to clear out the first gate-keep. The floor is a foul bed of disease. By the time you kill the rats and shovel out the remains and rat poop it is now evening. You didnt notice the gemstones in the rat poop you shoveled into sacks (50% of 0-400 gemstones worth 0-400,000gp). They were just gravel covered in disease.
Thats when six ghouls clamber up out of the swamp from under the bridge to dine on rats and find your Player Characters trying to fit the doors back on their hinges. Any treasure these ghouls have is off in their nest and there is no way in hell you would go visit a nest with another ten ghouls somewhere in the swamp around the castle.
You and your companions begin to wage war with the occupants of the second Gate keep: (60) Orcs and (24) hobgoblins. They got to their gate keep by boat coming across the swamp. Treasure-wise they are poor. They have treasure that amounts to 6,000cp, 4,000sp, 4,000ep and the Orc Commander had 4gp (2,464gp worth).
Throw in a staircase trap that drops you twenty feet taking 2d6 damage as you land on the slide and then you drop another twenty feet down into a room filled with swamp water (a ghoul feeding area on a lower dungeon level) all because a PC pulled the chimney flu lever in the fireplace on the second floor barracks setting the trap.
Note: factoring in experience point adjustments for PCs prime requisite adjustments you should encounter:
6 ghouls, 24 hobgoblins (1x 5HD hobgoblin King, 2x 4HD bodyguards), 60 Orcs (14x 1HD adult males, 15x 1HD adult Females, 30x Orc children, 1x 4HD Orc Chieftan), 5,000 Normal Rats. The three groups should occupy their own gate keep with Ghouls in the swamp below preying on the Rats as easy food. Morbundus level One is basically the bridge out to the Castle.
And that is Level One of Castle Morbundus by the Numbers...potentially wealthy, but given most early players wouldnt violate that human taboo of searching through a river of diseased rat shit for gravel, its unlikely they even know there are gems by the shovel load.
Addendum: The amount of time in the game it takes to swing a sword (one round) means that there are five thousand rounds (minimum) required to kill every rat. Thats sixty rounds per ten minute turn, six turns per hour, or just short of fourteen hours of 'splat the rat'. Sure you can share the load between your sword capable PCs and get that down to five hours between three fighter types, but you can clear that gate keep in a few minutes with a bunch of fireball spells. One Magic-user with a wand of fireballs can make a hell of a difference.
Ecosystems: Given Rats must exist here-their nest needs a food source and that would be garbage dumped by the orcs and hobgoblins in the second gate keep. There is also the likelyhood that rats feed on a food source like shreikers (the screaming mushrooms) and each other. The shriekers in turn feed on rat poop. And the Ghouls feed on the Rats. So throw in a forest of perpetually screaming shriekers - allowing rats to climb shriekers on the walls and ceilings - to fill out the gygaxian ecosystem