The Mansion on O Street & O Street Museum Foundation in Washington, D.C. offers a unique luxury boutique hotel experience within five interconnected townhouses, featuring over 100 rooms and 70 secret doors. Known for its eccentric decor, each room is uniquely themed, and virtually everything within the mansion is for sale. It functions as a hotel, museum, private club, and event space, having hosted historic figures like Rosa Parks and showcasing memorabilia from icons like John Lennon.