There is a discussion thread about Lotus Spa, the name on the advert here. It refers to 92A Northbrook street in Newbury. That is the main shop street and busy. The access appears to be besides Santander at the rear and the 92A is well signed, it is right by a multi storey carpark. You could enter 92A having parked in the multi storey, walk out with the Santander on your right but before going under a building arch in the alley turn right to see 92A sign and not be seen in the main shop street. Hope that local knowledge helps.
ah perfect thank you, because they've removed the detailed text from their advert and the map is general area type not accurate, and as you said northbrook street is the main highstreet, with many alleyways with metal stairs to flats above

Streetview not ideal, as it stops on the highstreet, and doesn't approach fully from the other side of the block, but it does show a handy placed cash machine in the alleyway you go through to get there

Map here that you can click through to interactive one then street view
External Link/Members Onlyalso shows very handy car park