
Sunbeamland was where it all began. This was the site of Richard Perry Son & Co's Jeddo Works, founded in 1790. John Marston purchased this business in 1871. It went on to become the home of Sunbeam bicycles and motorcycles until 1937.
The factory is in the triangle formed by Jeddo, Paul and Pool Streets, Wolverhampton. These streets are on the corner of the Penn Road (A449) and the Wolverhampton city ring road. In the A-Z Street Atlas of Birmingham, the factory is on map 29, H2.
If you have Google Earth, you can see recent satellite images of the Sunbeamland site by opening this .kmz placemark file:
Photographed on 28 April 1998.
There's a bit of artistic licence involved here. From Robert Champ's Illustrated History of Sunbeam Bicycles and Motorcycles.
If you visit the Moorfield Works and Sunbeamland, you should also see St John's Retail Park. Seriously. This is good.