If you are making a long weekend of it or wanting to explore local places on the Sunday then below are some suggestions!
There are also some popular walking trails here: https://www.alltrails.com/england/oxfordshire/bicester/walking
Blenheim Palace
Woodstock, England OX20 1PS, United Kingdom
Port Meadow
Webb's Close, Wolvercote, England OX2 8PU, United Kingdom