# The protected city

> Twenty thousand places London is not allowed to change.

- Category: Housing
- Cadence: monthly
- Status: Published on a monthly cadence.
- Dataset key: `heritage-points`
- Source: [MHCLG](https://www.planning.data.gov.uk/)
- Licence: Open Government Licence v3.0 — [terms](https://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/)
- Canonical page: [https://londongraph.com/g/the-protected-city](https://londongraph.com/g/the-protected-city)
- Machine-readable record: [https://londongraph.com/data/the-protected-city](https://londongraph.com/data/the-protected-city)

## 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.

## Visualisations

- [Map](https://londongraph.com/g/the-protected-city): Twenty thousand places London is not allowed to change.
- [Hotspots](https://londongraph.com/g/the-protected-city?view=hotspots): Compare the same measure geographically.
- [Breakdown](https://londongraph.com/g/the-protected-city?view=breakdown): Summarise the categories represented by the mapped records without loading every coordinate.

## Citation guidance

Attribute the original publisher named above and identify LondonGraph as the visualisation and methodology layer. Do not describe live values as a historical census, and do not present placeholder values as observations.