{"schemaVersion":"1.0","id":"the-protected-city","dataset":"heritage-points","title":"The protected city","description":"Twenty thousand places London is not allowed to change.","methodology":"Every listed building, conservation area, scheduled monument, registered park and world heritage site inside the 33 London authorities, from planning.data.gov.uk. Listed buildings come from Historic England's national list and are coloured by grade — Grade I is roughly the top 2.5% nationally, so a linear colour would lose them among the Grade IIs. Each entity is drawn at its published centroid, which for a conservation area is the middle of an area rather than a building.","category":"housing","categoryLabel":"Housing","cadence":"monthly","placeholder":false,"landingPage":"https://londongraph.com/g/the-protected-city","markdown":"https://londongraph.com/g/the-protected-city/index.html.md","source":{"name":"MHCLG","url":"https://www.planning.data.gov.uk/","licence":"Open Government Licence v3.0","licenceUrl":"https://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/"},"updatedAt":"2026-07-31T23:58:58.332Z","release":{"label":null,"publishedAt":null,"resourceUrl":null,"methodologyUrl":null,"sha256":null},"observations":null,"areaStatistics":null,"visualizations":[{"id":"overview","label":"Map","description":"Twenty thousand places London is not allowed to change.","url":"https://londongraph.com/g/the-protected-city","renderer":"primary","default":true,"timeControl":"inherit","datasets":[],"transform":null,"controls":null,"metrics":[],"caveat":null},{"id":"hotspots","label":"Hotspots","description":"Compare the same measure geographically.","url":"https://londongraph.com/g/the-protected-city?view=hotspots","renderer":"spatial","default":false,"timeControl":"inherit","datasets":[],"transform":null,"controls":null,"metrics":[],"caveat":null},{"id":"breakdown","label":"Breakdown","description":"Summarise the categories represented by the mapped records without loading every coordinate.","url":"https://londongraph.com/g/the-protected-city?view=breakdown","renderer":"geo-summary","default":false,"timeControl":"inherit","datasets":[],"transform":null,"controls":null,"metrics":[],"caveat":null}],"availability":"metadata-only","note":"No observation series is available from this deployment. The source and methodology metadata remain authoritative."}