The Secretary of the Interior is authorized to construct a visitor center and such other related facilities as may be deemed necessary to facilitate visitor understanding and enjoyment of the New River Gorge National River 1 and the Gauley River National Recreation Area in the vicinity of the confluence of the New and Gauley Rivers. Such center and related facilities are authorized to be constructed at a site outside of the boundary of the New River Gorge National River 1 or Gauley River National Recreation Area unless a suitable site is available within the boundaries of either unit.