See how William K Vanderbilt II (the great-grandson of shipping magnate 'Commodore' Cornelius Vanderbilt) lived in his Eagle's Nest 19th-century mansion, or take in a planetarium show.
A general admission ticket (adult/child $12/8) is available for the grounds and 80% of the mansion, which includes three museums (the other 20%, which includes the living quarters, are accessible via tour only) and a fourth museum outside the mansion. Look out for Vanderbilt's 3000-year-old Egyptian mummy and sarcophagus purchased in 1932 for E£280 (about $16).