Monks Wood Wilderness was a regularly ploughed field 60 years ago. Then (for whatever reason) it wound up without clear ownership and became an environmental study well ahead of its time: a rewilding project decades before the term was first coined.
This isn't all that surprising; plenty of places have looked into how areas respond to varying levels of intervention, both human and faunal, plus it provided a good excuse for the local council to simply ignore any questions around land management. Still, it's an interesting and useful study that proves how fast rewilding can occur.
The field in question benefitted from being adjacent to existing mature woodland, but even so, it's now a fully functional late-stage oak wood, with populations of rare species including marsh tits and purple hairstreak butterfly. There are over 400 trees per hectare, many of which are oak, and strong populations of deer, songbirds, bats, and insects. All in just 60 years. Imagine what would happen if the government started rewilding thousands of similar pockets of land?
The original council note that kickstarted efforts:
It might be interesting to watch what happens to this area if man does not interfere. Will it become a wood again, how long will it take, which species will be in it?