Civil engineering is the application of physical and scientific principles for the design, development, and maintenance of both the constructed and the naturally built environment. This includes infrastructure such as airports, bridges, buildings, canals, dams, pipelines, power plants, railways, roads, sewage systems, and more. Civil engineering projects can come through the public sector, from government agencies, or through the private sector. They can be either large or small in scale, with civil engineers working in fields such as planning, budgeting, project and asset management, research, analysis, and more. Civil engineering is the second-oldest engineering discipline, which has been created to differentiate civilian from military engineering. As a result, civil engineering is a broad discipline broken down into several sub-disciplines. The broad nature and long history of civil engineering mean that its growth as a discipline is closely associated with the development of human knowledge in areas including physics, mathematics, structures and construction, geography, geology, hydrology, environmental and materials sciences, mechanics, and more. Scientific principles, such as those developed by the ancient Greek Archimedes of Syracuse, were applied as they were understood, helping to drive engineering forward, which continues to this day with innovations and research. To better understand civil engineering today, it is worth taking a quick look at how it developed into a profession over the years.