If you have 2-3 hours to spend in Stevenage, here are some suggestions for things to do:
1. Visit the Stevenage Museum - this small museum showcases the history of the town and is free to enter. Allow 1 hour for a visit.
2. Take a walk around the town centre - Stevenage has a pedestrianised town centre with shops, cafes, and restaurants. Allow 1-2 hours for a leisurely stroll and some shopping or dining.
3. Visit Fairlands Valley Park - this large park has a lake, play areas, and walking trails. Allow 2 hours for a walk around the lake or a picnic.
4. See a film at Cineworld - this cinema is located in the town centre and has multiple screens. Allow 2-3 hours for a film and some snacks.
Overall, the best way to spend 2-3 hours in Stevenage would be to combine a visit to the Stevenage Museum with a stroll around the town centre and some shopping or dining.