A large copse of tall, redwood-like trees grows directly out of the shallow water, criss-crossed with a number of wooden boardwalks. Nearby is a small rocky outcropping, on which stands a large wooden windmill. The windmill pumps water into a holding tank, which then flows through pipes along the boardwalks to drive several motors. A spiral staircase driven into one of the trees, as well as an elevator driven by one of the water-powered motors, lead up to the treetops. On this second level are a number of huts, connected by rope bridges. Some are rectangular longhouses built between trees, while others serve as junctions that are built around individual trees.
A separate elevator leads up to a third level, where Sirrus and Achenar had individual bedroom structures. Sirrus's is a lavish affair, with a large comfortable bed and ornate furniture. Achenar's, meanwhile, is very bare-bones, with only a basic bed frame and mat. Achenar's side of this area also hosts a separate "temple" structure, with a holographic projection of Achenar speaking in tree-dwellers' language above a saw-toothed offering altar.
Finally, a third elevator leads from the boardwalk level into an enclosed room which houses the Myst Linking book.
Long ago, Channelwood was an island populated by a humanoid race and a more ape-like race. Both were sapient, and they shared the island peacefully; the humans lived on the ground, and the apes in the trees. According to the Age's only remaining human inhabitant, the island began to quickly sink into the ocean one day. Through a mechanism that has not been explained, the humans supposedly stopped the island from sinking entirely, saving the tree-dwelling apes but sacrificing themselves in the process. The few who remained moved into the trees, but were ill-suited for life there, and slowly died out.
When Atrus first linked to the Age, this story was relayed to him by the last human survivor, who had grown very old. The tree-dwellers revered him, and he lived on his own in a special hut. Once he finished telling Atrus the history of the Age, he walked off of the bridge connecting his home to the rest of the tree-dwellers' village, and died when he landed on the walkway far below. The tree-dwellers buried him at sea. Somehow, this burial also caused the Age's ocean to stop shifting colors, and it became a constant dark blue-green.
Atrus eventually brought his sons to visit the Age, sometimes for extended periods. He remarked that they were able to learn the language of the tree-dwellers much more easily than he could, and was happy to leave his sons in their care. He also helped build new hydro-electric elevators and a windmill to power the pumps that sent water along the ocean-level boardwalks.
Despite once hosting a healthy population, Channelwood is now entirely abandoned. It is likely, based on the trophies and other horrors in Achenar's room on the Mechanical Age, that they were all killed when the brothers plundered the Ages of Myst.