The soap used to be filmed in Esholt village in Bradford but as of 1996 they moved to a purpose built set at Harewood house estate in Leeds, the 2 sites are only a few miles apart thats why everything else remained the same like Home Farm.
Most of the other buildings like Home Farm, Sugdens, Dingles, King's, Old Church and Holiday Village are all located very close to the new village, and the scenes on the credits are surrounding countryside shots that are around the Otley, Pool and Harrogate area.
The viaduct is very close to the village and is on the A658 near Castley, have a look at the multimap link.
http://www.multimap.com/map/browse.c...1&scale=100000
Hope this helps.
Darren Hosker