The Humble Book Bundle: Summer of Adventure by AdventureKEEN just launched on Wednesday, July 19 at 11 a.m. Pacific time! Summer is here and we teamed up with AdventureKEEN to help you make the most of it. Get ebooks like Rail-Trails Hall of Fame, UG Las Vegas 2019, UG Universal Orlando 2019, and 101 Amazing Sights of the Night Sky.