Jackson's Station Garage, High Street, Ongar, Essex

I don't know if this ever was a petrol station in the past or not but there's a chance! Streetview seems to show a couple of metal covers on the forecourt surface, and it's certainly wide enough for there to have maybe once been a pump or two and still leave access to the main building behind.

www.google.co.uk/maps/@51.7088163,0.2446708,3a,75y,80.43h...

Done