While compound city isn't a proper geographic term, it is a fitting description for large cities with multipe well-defined and sometimes semi-autonomous administrative sub-divisions. For example New York is composed of 5 boroughs, and Tokyo is a vast conglomerate of 23 special wards as well as numerous cities, districts, and subprefectures. It is often hard to find machine-readable data on the boundaries of these sub-divisions, and rarely are such data ever organized to highlight the logical hierarchy of the areas. This repository aims to collect boundary polygons for such compound cities. Currently it contains administrative boundary geoJSON data for:

• New York City
• London
• Tokyo

FeatureCollections of the compound city subdivisions have been split into multiple files (one geoJSON per the features of each subdivision). For example, Greater London has a three level heirarchy with boundary files avaialbe for entities at each level.

• Greater London
  • Inner London
    • Camden
    • Greenwich
    • Hackney
    • Hammersmith and Fulham
    • Islington
    • Kensington and Chelsea
    • Lambeth
    • Lewisham
    • Southwark
    • Tower Hamlets
    • Wandsworth
    • Westminster
    • City of London
  • Outer London
    • Barking and Dagenham
    • Barnet
    • Bexley
    • Brent
    • Bromley
    • Croydon
    • Ealing
    • Enfield
    • Haringey
    • Harrow
    • Havering
    • Hillingdon
    • Hounslow
    • Kingston upon Thames
    • Merton
    • Newham
    • Redbridge
    • Richmond upon Thames
    • Sutton
    • Waltham Forest

http://www.nyc.gov/html/dcp/html/bytes/meta_dis_nyborough.shtml

http://www.ordnancesurvey.co.uk/oswebsite/products/boundary-line/index.html http://www.ordnancesurvey.co.uk/oswebsite/docs/licences/os-opendata-licence.pdf

http://www.esrij.com/products/data/japan-shp/

ESRI Japan, via The Ministry of Internal Affairs and Communications and The Ministry of Land, Infrastructure and Transport.