Probably the most obvious thing about this place is the very large number of Lesser Vargouille (worth 200 XP a piece) seemingly waiting to attack the party. Other than that, there's nothing special about this crypt except for 510 coppers in a box in the center of the room and Punch Daggers of Moorin found in a pile of bones and dust. Its entrance can be found at X=3200 Y=650.
While the Lesser Vargouilles appear to spawn infinitely, there is in fact a finite number of them. If the party leaves the crypt after killing any amount of Vargouilles, their progress in thinning the beasts' numbers is preserved. It can therefore be helpful to kill only some Vargouilles, rest and restock and come back later to finish the job.