Coordinates : 51 ° 38 ′ 13 ″ N 1 ° 12 ′ 40 ″ W \ / 51.637 ° N 1.211 ° W \ / 51.637 ; -1.211 Long Wittenham is a village and civil parish about 3 miles ( 5 km ) north of Didcot , and 3.5 miles ( 5.6 km ) southeast of Abingdon .
Coordinates : 51 ° 38 ′ 13 ″ N 1 ° 12 ′ 40 ″ W \ / 51.637 ° N 1.211 ° W \ / 51.637 ; -1.211 Long Wittenham is a village on the south bank of the River Thames in South Oxfordshire .