Craftland.org

I had started building a secondary town called "Arborton" with clearly defined walls and signs denoting it as claimed property. I had also done a fair amount of landscaping to flatten the land as well as planted a large square of trees to serve as a main part of this city. After being gone for a few days, I returned to find that somebody had built on it, destroyed my signs, and had the region protected.

Could somebody please correct this?