Ferropolis is nice to visit and great for photographing if you like old machinery. You can get there by taking the train to Dessau Hauptbahnhof (stop and see the Bauhaus museum there) and then bus 331 (direction: Gräfenhaininchen) which stops at Ferropolis.
Thanks Hal, the Bauhaus museum sounds like another strong reason to visit this area. Looking forward to see your Ferropolis postings in the gallery ;-).