A shining example of Jacobean architecture, the home of the 7th Marquess and Marchioness of Salisbury is a summer Hertfordshire favourite. Hatfield House offers tours of the residence and walks within the grounds from Easter Sunday until the end of September every year. The State Rooms can be looked around in your own time on weekends (only available on tours during the week), and the house offers a lovely river cottage kitchen and deli for lunch.