Sources and map credits

This curated collection covers selected UK editions, with uneven coverage by country, discipline and month. Each event displays its own source-check date. Organiser pages and check dates accompany each event; always use the organiser’s current entry and start instructions. Pins represent documented venues or postcode centroids, not precise race starts. Northern Ireland editions currently appear in the list without postcode pins.

Dates, advertised distance categories and separately verified ascent or overall cut-offs are sourced from official organiser or governing-body pages. Provisional editions are withheld. No organiser photographs, logos or route files are reproduced. This is an independent discovery tool, with no implied organiser endorsement.

Map rendering: MapLibre GL JS. Basemap: OpenFreeMap, © OpenMapTiles, data from OpenStreetMap contributors (ODbL). Terrain: Mapterhorn and its source attribution. Terrain is exaggerated for visual exploration and is not a navigation or elevation-measurement tool.

Great Britain postcode locations: Postcodes.io, source licences. Contains Ordnance Survey data © Crown copyright and database right 2025. Contains Royal Mail data © Royal Mail copyright and database right 2025. Contains National Statistics data © Crown copyright and database right 2025. Contains NRS data © Crown copyright and database right 2025. Northern Ireland postcode-derived coordinates are withheld from this release pending appropriate commercial-use permissions.

Two representative venue locations use Wikidata structured coordinates (CC0), checked against named organiser venues. These are approximate discovery locations. Calendar downloads contain all-day race-option reminders; verify start times and entry availability with the organiser. Sharing links preserves the selected filters or race, without an account.

Two Excalibur venue-area pins are calculated from the Natural Resources Wales car-park grid reference using the OS approximate coordinate transformation. The source grid has 100-metre precision; these pins do not identify surveyed race start lines.

Shortlists and packing plans

Shortlists save up to six race-option identifiers in this browser’s local storage when available. Removing options updates that local copy. Share links include selected race identifiers and filters; anyone with the link can open them. No account is created. Nearby discovery uses researched venue pins and approximate straight-line distances; unmapped events are excluded. It does not request your location or provide travel distances.

Packing plans separate source-linked organiser requirements from editorial suggestions. Some lists are partial or unconfirmed. Recheck final participant instructions before race day. Tick boxes stay on the current page and are not transmitted or included in shared links. Calendar files are date reminders only.

Privacy and corrections

No account, equipment inventory or location permission is needed. Map tiles are requested from OpenFreeMap and Mapterhorn; the rendering library loads from unpkg and fonts from Google Fonts. These providers receive ordinary web requests including network address. The standalone atlas adds no advertising trackers or analytics. See the providers’ privacy policies and the website privacy page.

Suggest a correction with an event, explanation and official URL. Do not include personal or sensitive information. Submissions are held privately in WordPress for editorial review; they do not directly change event records. A hashed network identifier is retained for up to one hour to limit repeated submissions. Catalogue updates require source review and a new release; there is no automatic organiser feed or promised daily verification.