Off the top of my head, China’s Great Clearance [1] and the Desert of the Duero in Spain [2]. IIRC the area north of Hadrian’s wall was also kept depopulated.

Off the top of my head, China’s Great Clearance [1] and the Desert of the Duero in Spain [2]. IIRC the area north of Hadrian’s wall was also kept depopulated. The Habsburg Military Frontier [3] could probably qualify too but the area was somewhat populated by soldier-settlers. [1] https://en.m.wikipedia.org/wiki/Great_Clearance https://en.m.wikipedia.org/wiki/Great_Clearance [2] https://en.m.wikipedia.org/wiki/Repoblaci%C3%B3n https://en.m.wikipedia.org/wiki/Repoblaci%C3%B3n [3] https://en.m.wikipedia.org/wiki/Military_Frontier https://en.m.wikipedia.org/wiki/Military_Frontier