In the City of Neftet, four portals can be found that are all called "Ancient Portal". They do, however, lead to different dungeons:

All these dungeons hold Catacombs portals. In three of the four dungeons, these portals lead to another section with similar creatures. In one dungeon, 21.0S, 7.5E - Ancient Portal, the Catacombs portals portal you back to the beginning of the dungeon.

For the different dungeons, see: