Links to existing miniature cities:

Swissminiatur, near Lugano, Switzerland:
Babbacombe Model Village, Devon, England
Bekonscot Model Village, Beaconsfield, England
The Model Village, Ramsgate, England
Mini-France, near Paris, France
Minimundus, near Klagendurt, Austria
Madurodam, The Hague, The Netherlands
West Cork Model Village
Pella-Miniature Dutch Village
Southport Model Railway Village
Miniaturk-Istanbul

http://en.wikipedia.org/wiki/Miniature_park

Also nice but totally different:

http://www.railzminiworld.com/

Links to suppliers and Garden Railroad magazines:
                                For excellent track, contact look at: www.svrronline.com
                                The Garden Railway Magazine: www.gardenrailways.com
                                For the friendlieest hotel in Athens, Greece: www.delphiarthotelathens.com
                                For the best waterpark suppliers, van Egdom at:www.vanegdom.nl
                                For the best general Cad software: www.designcad.com