The Sahuagin Stronghold

The fortress and former home to the lizardfolk is a rocky island located at the mouth of the Javan River. When the lizardfolk laired there, the island was almost entirely above sea level. Thadrah, the sahuagin high priestess of Sekolah, worked ritual magic that sank the island by lowering the seabed.
The cave entrance that once provided the lizardfolk access to the lowest level of the island caves has been submerged in 80 feet of water. The stone causeway that previously led from the shore to the cave entrance now leads to a new set of stone doors built by the sahuagin.
The fortress depicted in this adventure is not a typical sahuagin settlement. This is a singular situation — an experimental, fortified base in coastal waters from which sahuagin forces can exert an iron hand of domination over all races inhabiting the adjacent waters and coastal region. If this experiment proves successful, the sahuagin plan to construct more bases of this sort until their control over all waters and coasts is complete, and maritime commerce is at their mercy.
The sahuagin have renovated the fortress to conform with their plans. The two lower levels of the fortress have been completed, with work on the uppermost level still in process. A further lowering of the seabed and a final internal reorganization will complete the preparations.
General Features: The work carried out by the sahuagin and their slaves on the fortress interior shows expert craftsmanship. The rock is clean and dressed; all surfaces are smooth, all corners are near-perfect right angles, and all floors are level (except in the cave portion of cave 60, which has been left natural, and parts of area 19). The uppermost dry level has an eerie, clinical air.
Decorative Tiles The walls and floors of rooms occupied by sahuagin of higher rank are tiled in various colors (see the individual room descriptions). The tiles are made from polished stone and colored with plant dyes and octopus ink.
Corridors and Rooms All corridors are 10 feet wide and 15 feet high. All the rooms are 20 feet high except for areas 37, 41, and 42 (30 feet high), area 53 (about 60 feet high), and area 60 (45 feet high in the cave proper, 30 feet high over the area at the top of the steps). All walls separating adjacent areas are 3 feet thick. Unless otherwise noted, construction consists of plain dressed stone.
Doors All doors are 4-inch-thick double doors made of dressed stone, 5 feet wide and 10 feet tall. Except where otherwise noted, each door has a handle consisting of a horizontal bronze bar set into the stone on each side of the door, about 4 feet above the floor. All doors open into the areas they border on metal casters that move along grooves cut into the stone floor.
Gates and Pillars All gates consist of bronze construction and are 10 feet wide by 10 feet high, except for the gate in the cave mouth of area 60, which is 20 feet wide by 20 feet high.
All pillars are made of smooth dressed stone, 3 feet in diameter, supporting the roof above. All archways are 10 feet wide and 10 feet high.
Illumination No permanent light sources exist inside the stronghold, since the sahuagin have no need of them. In areas where slaves work, light is often necessary for their sake. If an area must be illuminated temporarily, the sahuagin fasten torches to the walls that produce light throughout the room. When the adventure begins, area 19 and area 37 are the only places in the fortress not shrouded in darkness.
Furniture and Seaweed Beds Items of furniture in the fortress are made of smooth, dressed stone unless otherwise specified. Coffers are 3 feet long by 2 feet wide and stand 2 feet high; they are used to store personal possessions.
Many of the area descriptions in levels 2 and 3 contain references to seaweed beds. These beds consist 10-foot-square patches of seaweed, growing from the floor and rising through the water to a height of 7 feet or more. An area occupied by a seaweed bed is heavily obscured.
Remember that the three-dimensional space in which a seaweed bed appears extends from floor to ceiling, and the seaweed occupies only the bottom half of that space. Thus, it’s possible for a creature to be in the same space as the seaweed without being inside the seaweed.