It consists of a wooden shack constructed from old ship parts, with an awning hung over its doorway. Outside of the shack can be found The Castaway, sitting in front of a campfire ablaze with green flames.
After the release of the 2.0.22 update, these areas showed signs of construction, with the appearance of old ship parts, wooden planks, barrels, and tools.
No further changes took place until the beginning of Season Three, when construction of the Castaway's Camp was completed.
The Castaway's Camp at Sanctuary Outpost.
A view of Plunder Outpost showing the Castaway's Camp at the bottom left.