Throughout 1950-1991, modern ballparks with newer architecture and conveniences were being built for teams in new cities and to replace some of the aging classic parks. New designs included cantilevered upper decks, plastic seating, symmetrical outfields, plain exteriors, dedicated parking lots, and luxury suite seating.
Beginning in the 1950s, as baseball began to expand to the west coast, the demand for ballparks with modern architecture and conveniences grew. The most notable influences were the cantilevered upper decks, the use of seating colors other than green, and fairly plain concrete exteriors. |Milwaukee County Stadium was the first to feature a symmetrical, round outfield fence. It also featured the rounded V-shaped grandstand and colorful seats that are common among all modern parks. Modern-style ballpark architecture continued throughout the 1960s, 70s, and 80s, introducing additional features such as multi-purpose stadiums, domed roofs, and luxury suite seating.
While most modern parks have been retired, a few, such as Dodger Stadium and Kauffman Stadium, have been hailed for aging beautifully. Rather than build new parks, the teams have decided instead to renovate the current structures, adding a few newer conveniences. Several of the modern parks built as such have remained in use, with no indication of being demolished. In 1991, construction of the New Comiskey Park marked the end of the modern-style ballpark architecture. Camden Yards in Baltimore was built the following year, which introduced baseball to a new \"retro-classic\" style of ballpark.