The Metropolitan Opera was founded in 1880. The Metropolitan is an America´s largest classical music organization, and annually presents some 240 opera performances. The home of the company, the Metropolitan Opera House is one of the premier opera stages in the world. The Met, as it is commonly called, is one of the twelve resident organizations at Lincoln Center for the Performing Arts.

Sources, related links:
Wikipedia - Metropolitan Opera
The Metropolitan Opera - official web site
Wikipedia - Lincoln Center for the Performing Arts
Lincoln Center for the Performing Arts - official web site
Met Opera Database