From the introduction:
Between the settled lands of the south and the wild country of the north is a stretch of forested uplands known as the Borderlands of Toth.
A land of wonder and beauty, danger and adventure, the Borderlands of Toth is the wilderness setting for several Adventure Modules, including The Ruins of Wyrmskull Keep, Chapel of Chaos, The Caverns of Corgoth and the Caverns of Corgoth Adventure Pack. This Adventure Module is also an enjoyable system for conducting wilderness travel and adventure throughout the borderlands, or wherever you choose to use the information. A setting and system for your wilderness travels and adventures, Borderlands of Toth brings you everything you need for travel, encounters, events and more.