ott age ▁industry . ▁By ▁ 1 9 7 5 , ▁this ▁had ▁led ▁to ▁the ▁almost ▁complete ▁disapp earance ▁of ▁the ▁far ming ▁sid eline . ▁In ▁ 2 0 0 4 , ▁only ▁eleven ▁far ms ▁were ▁still ▁being ▁worked ▁as ▁main ▁income ▁ear ners , ▁mostly ▁to ▁grow ▁as par ag us , ▁and ▁four ▁were ▁still ▁being ▁worked ▁as ▁a ▁sid eline . ▁ ▁Besides ▁le ather working , ▁metal working ▁also ▁locally ▁became ▁a ▁field ▁of ▁endeav our ▁at ▁roughly ▁the ▁same ▁time ▁to ▁supply ▁bel t ▁bu ck les , ▁suit case ▁handles ▁and ▁such like . ▁Major ▁works ▁were ▁located ▁in ▁We isk ir chen , ▁J ü ges heim ▁and ▁Nieder - R oden . ▁Now ad ays , ▁though , ▁le ather ware ▁manufact uring ▁and ▁metal working ▁play ▁only ▁a ▁sub ordinate ▁rôle . ▁ ▁In ▁ 1 9 5 4 , ▁a ▁new ▁field ▁of ▁industry ▁for ▁this ▁region ▁established ▁itself ▁on ▁D uden hof en ' s ▁out sk ir ts , ▁the ▁D uden hof en ▁Sand ▁L ime ▁Works ▁( K al ks and stein werk ▁D uden hof en ), ▁which ▁quar ried ▁the ▁fine ▁d une ▁sand ▁available ▁there ▁for ▁making ▁up ▁to ▁ 7 3 ▁million ▁br icks ▁in ▁one ▁year . ▁In ▁the ▁ 1 9 9 0 s ▁the ▁company ▁shift ed ▁its ▁production ▁focus ▁to ▁manufact uring ▁por ous ▁concrete ▁pres icion ▁blocks ▁( Plan ste ine ), ▁today ▁known ▁under ▁the ▁name