Stanford in the Vale is in South Oxfordshire, located off the A417, roughly half way between Faringdon and Wantage.
The village hall is not easy to find if you are driving through, but is situated on Hunters Field, the road that runs behind St Denys' church yard.
For clearer directions than we can give, the fantastic Stanford in the Vale comunity website has a good page here, and the exact location of the hall here
If you prefer a Google Maps link here