Outdoor literature is a literature genre about or involving the outdoors. Outdoor literature encompasses several different subgenres including exploration literature, adventure literature, mountain literature and nature writing. Another subgenre is the guide book, an early example of which was Thomas West's guide to the Lake District published in 1778. The genres can include activities such as exploration, survival, sailing, hiking, mountaineering, whitewater boating, geocaching or kayaking, or writing about nature and the environment. Travel literature is similar to outdoor literature but differs in that it does not always deal with the out-of-doors, but there is a considerable overlap between these genres, in particular with regard to long journeys.