Two-dimensional materials such as graphene offer a wide range of outstanding properties but are highly sensitive to disorder from the environment. We have developed techniques to stack 2D materials on top of each other to create ‘van der Waals Heterostructures’ with nearly perfect interfaces. Moreover, we can achieve high-quality contacts to the one-dimensional edge of buried layers. This talk will first describe the techniques used to create such heterostructures. Next, four application areas will be described: 1. Near-ideal performance achieved in graphene through encapsulation in insulating boron nitride (BN); 2. Applications in plasmonics, photonics, and light emission; 3. Greatly improved measurements of the electrical transport in semiconducting MoS2 through BN-encapsulation; 4. Measurements of air-sensitive 2D metals, including charge density wave materials and superconductors.