From OpenStreetMap Wiki
Jump to navigation Jump to search
Public-images-osm logo.svg defensive_works
Vestingwerken schema.svg
Military constructions or buildings designed for the defence of territories in warfare Show/edit corresponding data item.
Group: Military
Used on these elements
may be used on nodesmay be used on waysmay be used on areasshould not be used on relations
Documented values: 2
Useful combination
See also
Status: approvedPage for proposal

This key is used to tag individual defensive structures mainly at historic/pre-modern  fortifications. It is intended for all structures that were built for the defence of territories in warfare. This includes fortified settlements as well as forts that are/were uninhabited during peacetime.

Values for defensive_works=* contain terms used in fortification engineering.[1][2][3][4][5]

How to map

Individual defensive works should be mapped as node Nodes at their centre, as way Ways along a centre line or as area Areas along the outlines. The best fitting method depends on the size and shape of the structure. They should be tagged with defensive_works=* and may receive additional tags.

Mappers are encouraged to combine this tag with other tags where they are relevant. If a structure is actively used by the military, it is recommended to add a military=* tag to it.


Key Value Description Statistics (Taginfo) Sample photo
defensive_works barbican A  barbican Barbakan Krakow z ulicy Basztowej 2.jpg
defensive_works bastion A  bastion. The tag defensive_works=demi-bastion also has minor usage. Komárno - Castle.jpg
defensive_works battery A  fixed artillery battery. Individual guns or cannons can be tagged with historic=cannon. Battery Ledyard Angel Island.JPG
defensive_works batardeau A [W]batardeau[6] PL Batardeau 2015.JPG
defensive_works caponier A  caponier Gorazda fortress ditch and caponier.jpg
defensive_works cavalier A  cavalier Malta - Birgu - Ix-Xatt tal-Birgu - Fort Saint Angelo (MSTHC) 02 ies.jpg
defensive_works counterguard A  counterguard Rochapea1.JPG
defensive_works counterscarp A  counterscarp Antwerpen Schansstraat fort VIII, reduit met droge gracht en contrescarp (links) - 391094 - onroerenderfgoed.jpg
defensive_works couvreface A  couvreface Maastricht, Linie van Du Moulin, droge gracht tussen couvreface Du Moulin & bastion Stadhouder 1.JPG
defensive_works crownwork A  crownwork Luchtfoto bourtange.jpg
defensive_works curtain_wall A  curtain wall. See also  Defensive_wall. Courtine dame blanche.JPG
defensive_works faussebraye A  faussebraye; a lower wall in front of the main defensive wall of a fortification Heusden onderwal.jpg
defensive_works glacis A  glacis Glacis field jersey.JPG
defensive_works hornwork A  hornwork Nicpmi-01514-1-birgu fortifications hornwork of the post of castile.jpg
defensive_works inundation_sluice A  sluice made for  military inundation Fort Everdingen Inundatiesluis.JPG
defensive_works lunette A  lunette or demi-lune is an  outwork in the shape of a half-moon. LünetteII 1.jpg
defensive_works moat A  moat that historically provided a fortification with a preliminary line of defence.

For moats filled with water, add the tags natural=water and water=moat.

Dourdan castle dry moat.jpg
defensive_works motte A  motte Launceston Castle - - 22242.jpg
defensive_works ravelin A  ravelin Vestingwerken P1060601.JPG
defensive_works redan A  redan Redan Naxxar 3.jpeg
defensive_works redoubt A  redoubt Ximenes Redoubt in Salina, Naxxar, Malta.jpg
defensive_works reduit A  reduit Reduit.JPG
defensive_works roundel A  roundel Rondella della Bacola.jpg
defensive_works tenaille A  tenaille Tenaille, Fort Manoel.jpg
defensive_works water_gate A  water gate Newport Castle.jpg
defensive_works User-defined Use technical terms in fortification engineering. All commonly used values according to Taginfo Table of Fortification, Cyclopaedia, Volume 1.jpg

Tags to use in combination

  • name=* - if a defensive structure is named. Do not use the name of the fortification to tag individual structures.
  • heritage=* - if the structure has a heritage status. If only the entire fortification has a heritage status, do not use heritage tags for individual structures.
  • building=bunker - if the structure is a  bunker
  • start_date=* - year of completion
  • abandoned=yes - if the structure has been abandoned and shows signs of decay
  • ruins=yes - if the structure is in ruins

Similar and related tags