OpenStreetMap tiles

OpenStreetMap tiles

• What: raster map tiles for the Leaflet trip maps.
• URL: https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png
• Auth: none. Follow the tile usage policy.
• Called from: assets/js/travel-map.js (Leaflet).
• Triggers: a map being shown; tiles load as the visitor pans and zooms (scroll-wheel zoom is off).
• Caching: browser HTTP cache only.
• Failure: the map shows a blank grey background with markers still drawn.
• Quirks: the policy requires a valid Referer, so do not set Referrer-Policy: no-referrer. Heavy or bulk use is forbidden. Attribution (© OpenStreetMap contributors) must stay visible; it is set in the tile layer options and repeated in the page credits.