When the game was invented and sold in a little woodgrain box, the author told us a required supplement was an Avalon Hill game called Outdoor Survival. This was a wilderness survival game that consisted of a hexagonal map system that players would travel around, trying to find their way back to civilization, all the while trying not to die of thirst or get eaten by bears. This game map was used as the first wilderness "hex-crawl" for what eventually became D&D. Later, Judges Guild took this to a whole new level with the Wilderlands series. For many years, hex crawling was just the way the game was played. This series brings that back, or supplements existing games that use that system of travel.
What a hex crawl is, literally, is a wilderness sandbox of areas, encounters and villages that players travel around in. It provides no story line, just hundreds of story hooks and possibilities.
These books provide a sub-setting in your own campaign world. They populate the world, and allow you to let your players explore that world, rather than just "travel 20 days" to the dungeon. Written by John Stater of NOD fame, each of these supplements details an area with a specific theme. Monster and NPC statistics are provided for each encounter area detailed.
Among the reasons many adventurers choose to end their days in the cannibal-ridden, hurricane-savaged isles of the south is the immense distance it puts between them and the terrible land beyond the Black Water. The Black Water is a great inland sea filled with black, viscous water that sits as still as death. Nobody but a fool would willingly cross the Black Water, save for the strange men who sail the black arks, but many fools have crossed those waters in search of a lost love or a secret taken to the grave, for beyond the Black Water and its grey shores lies the icy Land of the Dead.