If you have 6 hours or a half day to spend in Welwyn Hatfield, here are some suggestions for things to do:
These well-preserved roman baths were discovered in the 1960s and are now a popular attraction. You can explore the remains of the bathhouse and learn about its history. Allow at least an hour for your visit.
This large park has an artificial beach, two lakes, and plenty of walking paths. It's a great place to relax and enjoy some fresh air. Depending on how much time you have, you could spend anywhere from an hour to the whole afternoon here.
This museum celebrates the history of the de Havilland aircraft company and has a wide range of aircraft on display, including a prototype of the de Havilland Mosquito. Allow at least two hours to see everything.
This National Trust property was the home of playwright George Bernard Shaw. You can explore the house and gardens and learn about Shaw's life and work. A visit here will take around an hour.
These are just a few ideas, but Welwyn Hatfield has plenty more to offer depending on your interests!