The Secretary of the Interior is authorized in his discretion to acquire for inclusion within the Mammoth Cave National Park by purchase, condemnation, or otherwise, any lands, interests in lands, and other property within the maximum boundaries thereof as authorized by sections 404 to 404b and 404c of this title, notwithstanding the provisions of sections 404b–1 and 404f of this title, or any action taken thereunder to exclude certain caves from the park area.