The Endangered Primate Rescue Center is supervised by the Frankfurt Zoological Society, and is home to around 180 primates (15 species in total), including 12 kinds of langur, plus three species of gibbon and two loris. All the centre’s animals were either bred here or rescued from illegal traders. Tours with a nature-conservation focus are on offer. Volunteers (experience not necessary, just enthusiasm) are encouraged to get in touch; tasks include preparing animal feed and cleaning enclosures. Your entry ticket also allows access to the Turtle Conservation Center. The centre has bred more than 180 offspring in all, from nine different species, including the world’s first captive-born Cat Ba langur, grey-shanked douc langur and Delacour’s langur. Because it's difficult to rehabilitate primates once they’ve lived in cages, only 30 or so gibbons and langurs have been released into semiwild areas (one site is adjacent) since the centre opened in 1993.