As used in this subchapter, the term—

((1)) “Secretary” means the Secretary of the Interior.

((2)) “Park” means the Wolf Trap National Park for the Performing Arts established under this subchapter, including the Center.

((3)) “Center” means the Filene Center in the Park. Such term includes all real property and fixtures which are within or directly related to the Filene Center.

((4)) “Foundation” means the Wolf Trap Foundation for the Performing Arts organized pursuant to the District of Columbia Nonprofit Organization Act.