Aster Cottage's postal address is:
Waterside,
Mere,
Wiltshire
BA12 6EE
Waterside is not a road, it is a path alongside a stream. There is no vehicular access to the cottage. Entering BA12 6EE into a sat nav may get you close, but parking is another matter.
The cottage on what3words: ///blaze.shams.proved
To access by road, see the following:
The best location is Upper Water St. Cars or small vans can use The Fields or Steep St.
Probably the best access point, a road with good access to the path. Enter BA12 6HD on a sat nav, or ///bulky.geology.clerics on what3words. Head up the path at the side of the stream for around 100 paces.
Access to the path, but parking not so good. Enter BA12 6ED on a sat nav, or ///zealous.parties.truffles on what3words. At the bottom of the hill turn right onto the path at the side of the stream.
A side path opposite a small car park which takes you almost to the front door of Aster Cottage. Enter BA12 6EA on a sat nav, or ///fitter.gong.reserved on what3words. Walk down the path opposite the car park, Aster Cottage is the final property on the left before the stream.
Another side path, brings you out a little way down and opposite Aster Cottage. Poor for parking. Enter BA12 6HP on a sat nav, ///locals.unrated.disprove on what3words.
Disclaimer: this is not an endorsement of what3words, an interesting idea poorly implemented. In my opinion. But it exists and can't be ignored.