# Strata — the library of ground

> A public library of local history, written one piece of ground at a time.
> Each entry covers a tile of about 1.2 x 0.6 km and is assembled from open
> sources: national and regional heritage registers, Wikidata, Wikipedia,
> OpenStreetMap, Macrostrat, newspaper and archive aggregators. 53
> localities, 109 published pages, 1157 sourced records.

## How it is organised

- `https://stratahistory.com/history/{country}/{locality}` — the canonical page for a place. It
  assembles every tile dug inside that locality into one record, and is the page
  to cite for anything about the place as a whole.
- `https://stratahistory.com/history/{country}/{locality}/{feature}-{key}` — one tile. Published
  only where it carries material its neighbouring tiles do not; otherwise it
  canonicalises to its locality. `{key}` is a stable hash of the tile, so the
  URL survives the narrative being rewritten.
- `https://stratahistory.com/library` — every locality, filterable by country and era.
- `https://stratahistory.com/digs/index.json` — the same list as JSON.
- `https://stratahistory.com/sitemap.xml` — sitemap index; `lastmod` is the date a page was
  last reviewed.

## What is on a page, and how far to trust it

Each page carries a short answer, a narrative in chapters, and a timeline of
discrete records. Every record shows its publisher and a link to the source, and
is marked with a confidence. Two things are true of everything published here:

- **Records** are sourced claims about that ground. Only high and medium
  confidence records are published; low confidence is excluded from the site.
- **Era background** is general context about a period, clearly marked, and is
  explicitly NOT a claim about that ground. It is set apart visually and labelled
  "Era background — not a record of this tile". Do not cite it as a fact about
  the place.

Narratives are composed by AI from those sourced records. They can be incomplete
and can misdate an event. Prefer the timeline records and their source links over
the prose when attributing a specific claim.

## Citable anchors

Every page's timeline is grouped by era, with one stable anchor per group, so a
layer can be cited rather than a whole page:

- `#deep-time` — Deep time
- `#prehistoric` — Prehistoric
- `#ancient` — Ancient
- `#medieval` — Medieval
- `#early-modern` — Early modern
- `#modern` — Modern

## What is deliberately absent

Published resolution is the tile, never a precise point, and no page records who
visited a place or when anybody was there. Nothing on this site is derived from
any individual's use of the app.

## Places with the most ground on record

- [Paris, France](https://stratahistory.com/history/france/paris) — 30 tiles, 289 records
- [Monza, Italy](https://stratahistory.com/history/italy/monza) — 6 tiles, 48 records
- [Lehi, United States](https://stratahistory.com/history/united-states/lehi) — 5 tiles, 47 records
- [Highland, United States](https://stratahistory.com/history/united-states/highland) — 5 tiles, 35 records
- [Sintra, Portugal](https://stratahistory.com/history/portugal/sintra) — 5 tiles, 21 records
- [Rome, Italy](https://stratahistory.com/history/italy/rome) — 4 tiles, 52 records
- [North Leigh, United Kingdom](https://stratahistory.com/history/united-kingdom/north-leigh) — 4 tiles, 47 records
- [Lisbon, Portugal](https://stratahistory.com/history/portugal/lisbon) — 4 tiles, 44 records
- [Cascais, Portugal](https://stratahistory.com/history/portugal/cascais) — 4 tiles, 27 records
- [Venezia-Murano-Burano, Italy](https://stratahistory.com/history/italy/venezia-murano-burano) — 3 tiles, 44 records
- [Salt Lake City, United States](https://stratahistory.com/history/united-states/salt-lake-city) — 3 tiles, 26 records
- [Florence, Italy](https://stratahistory.com/history/italy/florence) — 3 tiles, 23 records
- [Tower Hamlets, United Kingdom](https://stratahistory.com/history/united-kingdom/tower-hamlets) — 2 tiles, 27 records
- [Misericordia, Portugal](https://stratahistory.com/history/portugal/misericordia) — 2 tiles, 26 records
- [City of London, United Kingdom](https://stratahistory.com/history/united-kingdom/city-of-london) — 2 tiles, 25 records
- [Dublin, Ireland](https://stratahistory.com/history/ireland/dublin) — 2 tiles, 24 records
- [Santa Maria Maior, Portugal](https://stratahistory.com/history/portugal/santa-maria-maior) — 2 tiles, 23 records
- [Windsor, United States](https://stratahistory.com/history/united-states/windsor) — 2 tiles, 20 records
- [Huairou, China](https://stratahistory.com/history/china/huairou) — 2 tiles, 5 records
- [San Jose, United States](https://stratahistory.com/history/united-states/san-jose) — 2 tiles, 4 records
- [Cremona, Italy](https://stratahistory.com/history/italy/cremona) — 1 tiles, 24 records
- [Innere Stadt, Austria](https://stratahistory.com/history/austria/innere-stadt) — 1 tiles, 18 records
- [Philadelphia, United States](https://stratahistory.com/history/united-states/philadelphia) — 1 tiles, 15 records
- [Santo Stefano, Italy](https://stratahistory.com/history/italy/santo-stefano) — 1 tiles, 15 records
- [Versailles, France](https://stratahistory.com/history/france/versailles) — 1 tiles, 15 records