hi there,
Most attractions in Delaware are open year-round, but some maybe close to the public during public holidays.
Self-guided
walking tours of historic neighborhoods can be done at your leisure, but the "A Day In Old New Castle" tour, is only offered one day a year in the month of May. There is no other day of the year when the private
historic homes and gardens are open to the public as such.
Hope this helps
Vacationbuddy