Mere of Dead Men

Mere of Dead Men
The Mere was located along the Sword Coast on the Sea of Swordsbetween Neverwinter and Waterdeep. The High Road skirted its eastern edges on its way through the foothills of the Sword Mountains to the east. The nearest significant settlement was Leilon to the north.

Description
As you round a bend in the foothills, you are greeted with a stunning vista, the peaks of the Sword Mountains on your left, the road continuing to weave along their boarder... and to the right, a seemingly endless sea of mists, punctuated every few hundred feet by dead trees, their branches reaching through the fog like so many clawed fingers reaching to the sky. The fog is too thick to see through from this distance, leaving the Mere of Dead Men shrouded in mystery.

As you travel further down the side of the hill and approach the Mere, it becomes increasingly obvious that the trek into this unhallowed ground will not be an easy one. Looking closely you see some painted sticks in the ground. As you approach one, you see another form from the mists ahead of you, marking a trail. You continue slowly through the thick mud, water filling your boots and the mists enveloping you in their cold embrace. The smell of rot and mold fills your senses. Every few feet you see the remnants of creatures who have ventured into the mists, never to return.

End of Day 1
As the sky begins to glow a deep red, marking the end of the day, the path comes to a small island It rises from the brackish pools around you, overrun with dead, twisted vegetation. Amongst the dead bushes and reeds, you find four wicker lean-tos and a stone platform. You also find three dougout caones that are drawn up next to one of the lean-tos. Looking past the abandoned camp a few dozen yards in the direction you have been travelling, dry land ends. Other than moss covered trees, fallen logs, thick clumps of weeds and some skeletal remains of various beasts, nothing rises above the quiet, black water. As you take in this sight, you realize that the cawing of crows has stopped, and you can no longer feel the breeze on your skin.

Day 2
As you pull away from the island, a clear path is marked in the trees to your destination marked by crude scrawlings depicting Tiamat carved into the dead bark. The branches growing thicker and ever more intertwined as you continue, the canopy tightening its bony grip around the small canoes you command. The water still as death. After a few hours of quietly rowing, the markings that you have been following give way to what appear to be humanlike figures hanging by nooses in the branches above, continuing to mark your way.

DM's Notes
The Mere itself was full of trees, vines, quicksand, and hidden islands, and it was generally covered in fog, making visibility very poor. The bones of fallen creatures were clearly visible throughout the Mere. The water was deep enough that it could be navigated on a flat-bottomed boat, but the dark water and hidden obstructions made that choice dangerous

Official Lore
Found here.