STRTree (Sort-Tile-Recursive Tree) Engine is an GeoSpatial index engine that uses bottom-up way to build an R tree for two-dimensional points. The STR tree packed R tree is simple to implement and maximizes space utilization; that is, as many leaves as possible are filled to capacity. Overlap between nodes is far less than in a basic R-tree. However, once the tree has been built, points cannot be added or removed.