It is 1,000 acres of rolling Delaware countryside, and the house alone has 175 rooms packed with American decorative arts. Delaware’s largest state park sits where the Delaware Bay meets the Atlantic Ocean, and the geography alone is worth the drive. Delaware Botanic Gardens At Pepper CreekDelaware Botanic Gardens opened in 2019 and already feels like it has been there forever. Combine this visit with a stop at Cape Henlopen or the Zwaanendael Museum for a full day in southern Delaware. Admission is free, which makes it an easy add-on to any trip to Cape Henlopen or the Delaware Botanic Gardens.