An outdoor theater with a semi-circular, fan-shaped, or elongated auditorium facing a grass, masonry, or wooden stage. The historic amphitheater took its name from the Greek amphi, referring to the seating “around” or “on both sides” of a performance space. It was oval-shaped with steep tiers of seats surrounding a flat event space, as found at the Coliseum in Rome. Ranging from small community facilities to large concert venues serving over 20,000, outdoor theaters gained popularity in the U.S. at the turn of the 20th century as a response to the commercialism of interior theaters. After World War II, the goal of building outdoor theaters to maximize contact with nature shifted to outdoor theaters as an economical alternative to indoor theaters. Their design may include stationary seats, turf terraces and/or a sloped lawn.