← Skerved Geo

Credits

Skerved Geo (geo.skerved.se) is a free practice tool by Vincent Skerved. Built with help from AI coding tools; curated and maintained by a human. Feedback: skerved@gmail.com.

App code is MIT-licensed. Third-party maps and media keep their own terms. This page lists everything redistributed in the site.

Natural Earth

World countries, capitals/cities points, peaks, lakes, rivers, admin-1 lines, US states, and the Russia outline are derived from Natural Earth (public domain), and shipped here as local SVG maps and quiz data. World - Peaks uses NE elevation points (50m/10m). World - Deserts uses NE geography-region desert/basin polygons (plus Mojave from OSM). World - Mountain ranges uses NE Range/mtn geography-region polygons (50m/10m), plus a custom Great Escarpment outline (see below). World - Seas & bays uses NE marine polygons (50m/10m). World - Archipelagos and World - Islands use NE Island / Island group geography-region polygons (50m/10m). World - Rivers and World - Lakes quiz maps use NE 50m river centerlines and lakes, plus NE marine/10m layers for Caspian Sea, Lago di Garda, and Crater Lake.

World - Mountain ranges (Great Escarpment)

The Great Escarpment quiz outline is derived from an illustrative map by Oggmus on Wikimedia Commons (CC BY-SA 3.0). The red stroke was pixel-extracted and approximately georeferenced for this practice map - not an official boundary. Changes were made (vectorization, simplification, map projection).

Flags

Country and US state flag SVGs from flagcdn.com / Flagpedia (Wikimedia Commons-based vectors), included in this site. Individual flags may carry their own Commons license terms.

Europe - Pedestrian crossings

Crossing-indication sign SVGs from Wikimedia Commons (per-file licenses; authors and terms on each file page; share-alike where marked SA).

Sweden - landskap

• Province boundaries: perliedman/svenska-landskap (CC0).
• Coats of arms (vapen): Wikimedia Commons SVGs (per-file licenses; Swedish heraldic rules may still limit how arms are used).
• Provincial animals and flowers: concept lists from WWF Sverige and Wikipedia (province flowers). Quiz photos are from Wikimedia Commons (mostly CC BY-SA 2.0-4.0, plus some CC BY / CC0 / public domain). Per-file source, author, and license: photo credits.

Sweden - kommuner

• Municipality polygons: okfse/sweden-geojson (reuse offered by that project; upstream Swedish open data).
• Population and tätort names in item text: Statistics Sweden (SCB) via their open data APIs.
• Seat pins on the map (municipality admin_centre nodes) from OpenStreetMap (© OpenStreetMap contributors, ODbL 1.0), via Overpass.
• Lakes on the map: Natural Earth (above).

Brazil

• State and region practice maps are SVG derived from official IBGE territorial meshes (Instituto Brasileiro de Geografia e Estatística, malhas API; open data with CC BY 4.0-compatible terms - credit IBGE).
• Phone-code (DDD) practice maps: the 67 numbering areas are built by dissolving the official IBGE municipality mesh according to Anatel's Plano Geral de Códigos Nacionais (PGCN) municipality-to-DDD assignments (Anatel open data - reuse with source credit).

US area codes (phone codes)

• Geographical NPA polygons from Esri’s USA Telephone Area Codes layer (FeatureServer), simplified into local practice SVGs. Use of the layer is subject to Esri’s item / Hub terms.
• City labels joined from ravisorg/Area-Code-Geolocation-Database when available.

Germany - Kreise

• Kreis and Bundesland outlines from VG250 - Verwaltungsgebiete 1:250 000 (© GeoBasis-DE / BKG, Bundesamt für Kartographie und Geodäsie), licensed under Datenlizenz Deutschland - Namensnennung - Version 2.0. Boundaries as of 1 January 2026, simplified into local practice SVGs. AGS ids identify Kreise.

Turkey - Belediyeler

• Province (il) and district (ilçe) boundaries from geoBoundaries gbOpen Türkiye ADM1/ADM2 (OSM-derived; ODbL 1.0 / © OpenStreetMap contributors), used as local practice SVGs.

World - Rivers & Lakes (OSM extras)

• Lake Maracaibo and Lake Ohrid polygons from OpenStreetMap (© OpenStreetMap contributors, ODbL 1.0), via Nominatim, merged into practice SVGs.

World - Peaks (OSM extras)

• A few peaks missing from Natural Earth elevation points (Kangchenjunga, Annapurna, Table Mountain, Mount Cameroon, Vesuvius, Cotopaxi, Popocatépetl) use coordinates from OpenStreetMap (© OpenStreetMap contributors, ODbL 1.0), via Nominatim.

World - Deserts (OSM extras)

• Mojave Desert polygon from OpenStreetMap (© OpenStreetMap contributors, ODbL 1.0), via Nominatim (absent from Natural Earth desert layer).

World - Seas & bays (OSM extras)

• Guanabara Bay polygon from OpenStreetMap (© OpenStreetMap contributors, ODbL 1.0), via Nominatim (absent from Natural Earth marine layer).

World - Straits & canals (OSM extras)

• Strait of Hormuz, Bering Strait, Sunda Strait, Strait of Gibraltar, and Drake Passage geometries from OpenStreetMap (© OpenStreetMap contributors, ODbL 1.0), via Nominatim (missing or weak scrap polygons in Natural Earth). Bab el-Mandeb and Yucatán Channel use hand-authored corridor polygons; Suez / Panama / Kiel use schematic hand-authored canal centerlines.

World - Islands (OSM extras)

• Cebu Island and Easter Island polygons from OpenStreetMap (© OpenStreetMap contributors, ODbL 1.0), via Nominatim (absent from Natural Earth island layer).

Japan phone codes

• Municipality boundaries from smartnews-smri/japan-topography (simplified), derived from MLIT National Land Numerical Information administrative zones (N03, CC BY 4.0). Dissolved into approximate landline trunk-prefix regions for practice SVGs.

Philippines

• Province boundaries (practice SVG): PSA Philippine Standard Geographic Code units via the OCHA/HDX COD-AB Philippines administrative boundaries dataset (Creative Commons Attribution for Intergovernmental Organisations, CC BY-IGO), cleaned and matched to PSA updates in altcoder/philippines-psgc-shapefiles then packaged as GeoJSON by faeldon/philippines-json-maps (James Faeldon; repository MIT covers the packaging, not a substitute for the HDX geometry terms). Provinces: 2023 vintage, all 82 current provinces plus Metro Manila.
• Motorcycle-plate region map (philippines-regions.svg): 2023 region outlines dissolved from faeldon/philippines-json-maps (2023/geojson/regions/…), which packages PSA/NAMRIA units via altcoder/philippines-psgc-shapefiles from the OCHA/HDX COD-AB Philippines dataset (Creative Commons Attribution for Intergovernmental Organisations, CC BY-IGO). The faeldon MIT license covers packaging only. BARMM is drawn as non-quiz context (no IRR motorcycle strip). Negros Island Region (NIR) is absent from this 2023 dissolve (re-established in 2024); the quiz follows the official strip table, which has no NIR strip.
• Province study list adapted from a Learnable Meta map (author όλδօ).
• Motorcycle plate strip images from plonkit.net / Philippines guide (template licenceplates.png), used with Plonk It's stated condition that guide resources may be reused when Plonk It is explicitly credited. Colour-strip rules also follow Philippine motorcycle plate regulations (RA 11235 IRR).

Indonesia

• Province / kabupaten geometry: mashadinoor/Indonesia-Geojson-2026 (MIT; BIG-derived data - see that repo).
• Regency codes/names: edwardsamuel/Wilayah-Administratif-Indonesia (BPS-style CSV).

Russia - city and town names

• Place list and transliteration aids from a Learnable Meta map by Vincent Skerved. Outline map from Natural Earth.

Other

• Short city/capital “fact” lines are original study notes written for this project.
• Free geography practice tool. Open data and media above are used as credited on this page.

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