My family and my neighbor's have lived in our homes for over 9 years. Both homes were new construction at the time. We were the last of the neighbors to move in and all other lawns were established, except for ours. We planted grass and landscaped (about $2000 worth of large trees, shubs and beds) along what everyone believed to be our lot line. Recently, our neighbor looked at arial photos of our lots and realized that his property cut through our backyard diagonally (aprox. 800 sq ft). Therefore all of our landscaping is clearly in the middle of his backyard and ours is no longer the rectangle that we once thought. The backyard size and shape was a deciding factor in purchasing this home 9 years ago. Luckily we have a very good relationship with our neighbors, but frankly they have been paying property taxes on land that they have not used for 9 years. What are our options? Do they have right to ask for back property taxes from us? Thank you!