Close to my (previous) workplace at Kelvin Grove campus of QUT is rainforest project dating from the late 1970s. Over the years, the formerly disused site had grown into quite a significant native habitat with a rich diversity of native flora and fauna for such a small site. In recent years, the site has stopped being used for educational purposes, so the university has blocked access. I guess there is a perceived insurance risk and no one wants to pay the premium. And while the university highly values the “built” environment, a place left to its own devices doesn’t figure too highly. In this case, the neglect is beneficial, as long as the area isn’t marked for redevelopment.
[Update: December, 2017] I returned to the site today and was pleased to see that the university has not only maintained the site, but have taken down the ugly barriers. It looks like someone is actively regenerating the area again.