"................And leads to the next obvious and rhetorical question - why
didn't they build the garden by a main transport/rail route?
(answers on a postcard to /dev/null :-) ............"

Like they did with the Eden Project?

Regarding Middleton(Look for Middleton on Google and the gardens come a long
way down the listings).

It is set in the former 18th century regency park of Middleton Hall in
Carmarthenshire, a 568 acre estate on the edge of the Tywi valley. The
Garden enjoys a pollution free environment, spectacular views of the
surrounding countryside and a rich cultural heritage.
But I suppose to have it in the middle of an Industrial estate would have
given it that something extra.......Like pollution and vandals.

--
David Hill
Abacus nurseries
www.abacus-nurseries.co.uk
***2004 catalogue now available***