Welcome | Nemours Mansion, Nemours is the 300-acre country estate of the late industrialist and philanthropist Alfred I. duPont. Located on the grounds of the renowned Alfred I. duPont Hospital for Children in Wilmington, Delaware. The mansion and gardens are open for tours between May and December. Tour groups are kept small and include expert commentary by guides familiar with the duPont family history. Their knowledge of the time period in which the estate was built allows the visitor to experience the ambience of the.