The Young Men's Christian Association (commonly known as YMCA or simply the Y) is a worldwide organization of more than 45 million members from 125 national federations affiliated through the World Alliance of YMCAs. Their main motto is: "Empowering young people." It was founded on 6 June 1844 in London, England, United Kingdom, and it aims to put Christian principles into practice, achieved by developing "a healthy spirit, mind, and body." The YMCA is a federated organization made up of local and national organizations in voluntary association. It is one of the many organizations that espouses Muscular Christianity. Today, YMCAs are open to all, regardless of religion, social class, age, or sex. The World Alliance of YMCAs is headquartered in Geneva, Switzerland.