Geohash so far: *00*

Geohash so far: 00*11*

Geohash so far: 0011*01*

Geohash so far: 001101*00*

db.cities.createIndex( { location: '2d', *bits: 4* } ) Default %bits% is 26, about 0.3 meter resolution (~½ * 40000 / 2^26~)