Bounding Box

A bounding box (or bbox) is the rectangular extent of a geometry — the minimum and maximum latitude and longitude that enclose it. Bounding boxes make spatial queries fast: filtering by a rectangle is far cheaper than testing against a complex polygon.

Neighbourly pre-computes a bounding box for every boundary, and viewport searches use bbox filters — expressed as south-west and north-east corners — to return everything visible in a map view.