My sorceror was doing a bit of exploring, and apologies for forgetting the exact name of this place, but there is a crawl space to a ruined temple on the Central Server where the spawns are snakes and vampire assassins.
I took the crawl space and entered the ruined temple where there are dark Spiders, snakes and a bind stone, and a hole that leads to Beneath the ruined temple (I think that is the name of it). When I arrived in the next area, these was a ladder leading up and a door leading into a larger room, which held more Dark Spiders.
After killing the spiders, I could find no way forward so returned to the ladders, but they were gone.
It is possible they were destroyed by the backlash of a fireball I fired into the spider room, but I would have been hit by it too and wasn't, so I am not sure why the ladders were not there on my return. It would be worth checking them to make sure they are supposed to remain and that they are not destroyable to prevent players becoming trapped there. If it is a trap, then apologies for this post.
Thanks to Mixafix for porting me out, and he destroyed the way down until the next server reset to stop others becoming trapped too.