Usufruct is a legal concept dating to Roman law: the right to use and enjoy the fruits of something one does not own. In its classical form it asks the holder to preserve the underlying thing rather than consume it.
A land-use right is a close cousin, but the analogy needs care. That “don’t diminish it” condition makes little sense for a location: its value is created by the surrounding community, not by the holder, and can’t be damaged or used up by ordinary use. What a land-use right secures for the community is simply the rental value of the location — nothing more. Everything you build or improve on the site is fully yours, because it is the fruit of your own labor and capital; only the location’s rental value returns to the community.