@sarahaxon I'd be more interested in knowing areas of land where I wanted to live couldn't be built on, rather than those that could. Yes, I'm a nimby. When I moved to my current home I had a good look at the surrounding terrain and realised it would be so costly for a builder to prepare a site that no one would consider it.
Life's too short to get irate at builders holding onto land to raise the value - it's no different to me investing hard cash to make a profit, as they'd have had to pay hard cash for it in the first place.
A large "parcel" of land near me recently came on the market for £1. The catch was that it is crisscrossed by historic social trails, has been mined, is downright dangerous to stray off the paths, and the new owner would be responsible for the safety of, and injuries sustained by, the public.....
It was eventually gifted to the people of the town as the owners simply wanted to get rid of what had become a liability, and is now "cared for" by "friends of the moor". No one to blame but yourself if you get yourself into trouble. Broadleaf trees are being planted, and non-native pines removed. It's got it's own stream and waterfall. I've even found where a kestrel nests... Perfect 🙂