Watch FilmoFlix. 'Behind The Garden Gate' is a documentary film about homegrown biodiversity and the challenges that come with it. In the 1970s Guus Lieberwerth and friends cleared a patch of agricultural wasteland in order to take care of rare and endangered plants and animals. ​Now, 50 years later nature is thriving within a hidden paradise just five minutes away from a city centre, but even closer to systemic pressures and land developers.