A major geographical focus of tourism planning and management is tourism destinations, and it is in destinations that tourists encounter and interact with the local community and the local environment. This interaction leads to impacts on the local population, the environment and also on the tourists themselves. As will be discussed in later chapters, these impacts can be beneficial in relation to, for example, the local economy. However, the encounter between tourists and the destination they are visiting can also lead to, for example, damage to the local environment. It is in relation to these impacts that much tourism planning and management is targeted. Subsequent chapters investigate these impacts. However, it is first necessary to understand how tourism destinations have emerged. This chapter critically assesses key theories which have contributed to our understanding of how tourism destinations have emerged, grown and in some cases declined. These theoretical perspectives can be useful in helping to understand the need for and nature of tourism planning and management.