The Sun Belt has seen substantial population growth since the 1960s from an influx of people seeking a warm and sunny climate, a surge in retiring baby boomers, and growing economic opportunities. The advent of air conditioning created more comfortable summer conditions and allowed more manufacturing and industry to locate in the sunbelt. Since much of the construction in the sun belt is new or recent, housing styles and design are often modern and open. Recreational opportunities in the sun belt are often not tied strictly to one season, and many tourist and resort cities, such as St. Petersburg, Orlando, Tampa, Miami, San Diego, Los Angeles, Las Vegas, Phoenix, and New Orleans, support a tourist industry all year.