The WeltWald Harz (120 hectares) up to 2009 Arboretum Bad Grund , also known as Exotenwald and sometimes called the Arboretum des Forstamtes Grund or the Forstaboretum der Niedersächsischen Landesforstverwaltung, is an arboretum located along the B 242 federal highway near the Hübichenstein, northwest of Bad Grund, Lower Saxony, Germany. It is open daily without charge.