The goal of this workshop is to bring together an international group of scientists interested in the future of gamma-ray astronomy to define the direction and discuss R&D projects for the next generation observatories such as CTA, HAWC and AGIS. This is the 4th workshop in the series of this kind with previous workshops being held in Los Angeles, Santa Fe and Chicago. The focus of the meeting will be to summarise the scientific motivations for such instruments, drawing on the White Paper for the Division of Astrophysics of the American Physical Society. Particular emphasis in the discussion will be devoted to technical challenges, design parameters and projected sensitivities of such future observatories.