The aim of this chapter is to give a brief overview on airports, as they are a fundamental facility to facilitate intermodal transportation and ensure that flights are performed in a safe way. Section 9.1 is devoted to define what airports are, providing a brief overview of their history, introducing their naming nomenclature, describing the variables that potentially affect the demand of air transportation, and thus the necessity of building an airport, in a determined location, and finally giving a description of the master plan, the set of official documents for the design and construction of an airport. Section 9.2 is devoted to provide a description of the configuration of a modern airport, including air-side and land-side elements. Finally, Section 9.3 analyzes airport operations. Some introductory aspects suitable for this type of course can be consulted in Franchini et al. . Two thorough references on the matter are De Neufville and Odoni , García Cruzado .