There is much interest in gas hydrates in relation to their potential role as an important driver for climate change and as a major new energy source; however, many questions remain, not least the size of the global hydrate budget. Much of the current uncertainty centres on how hydrates are physically stored in sediments at a range of scales. This volume details advances in our understanding of sediment-hosted hydrates, and contains papers covering a range of studies of real and artificial sediments containing both methane hydrates and CO2 hydrates. The papers include an examination of the techniques used to locate, sample and characterize hydrates from natural, methane-rich systems, so as to understand them better. Other contributions consider the nature and stability of synthetic hydrates formed in the laboratory, which in turn improve our ability to make accurate predictive models.