def bbox_geohashes_shapely(bbox_pts, accuracy=5):
        """
        Given a list of lat/lon points marking the bounding box, return all geohashes within the box.
        Bounding box can be an arbitrary simple polygon (i.e., any number of sides are okay, but inclusions are not).

        To see geohashes overlaid on map, visit http://geohash.gofreerange.com/

        All bounding points are checked for in/out.  After converting bounding points to geohashes, all neighbors
        are checked for presence in/out of bounding box.  Neighbors of those points still inside are also checked,
        until no more points remain.

        Parameters:
        -----------
            bbox_latlon   : list of [lat,lon] points
            accuracy      : length of geohash

        Returns:
        --------
            inside  : set of hashes contained within bounding box

        """
        import geohash
        import shapely
        from shapely.geometry import Point

        unchecked = set()
        inside = set()
        outside = set()

        for pt in bbox_pts:
            tst_gh = geohash.encode(pt[0], pt[1], accuracy)
            unchecked.add(tst_gh)

        bbox = shapely.geometry.Polygon(bbox_pts)
        while unchecked:
            this = unchecked.pop()

            if bbox.contains(Point(geohash.decode(this))):
                inside.add(this)

                for gh in geohash.neighbors(this):
                    if (gh not in inside) & (gh not in outside) & (gh not in unchecked):
                        unchecked.add(gh)

            else:
                outside.add(this)

        return inside