CastleScotland.app is a free, independent online guide to Scottish castles, tower houses and historic ruins. Created in Edinburgh and built around first-hand visits and original photography, it brings together concise historical introductions, practical visitor information, an interactive map and themed collections to help the public explore sites across Scotland.

Individual guides cover places, owners and families, architecture, sieges and military events, royal connections, restoration, legends and screen locations where relevant. Entries also include access details, condition, location and trip-planning information. The resource is intended for people interested in local history, independent travellers, history enthusiasts and photographers. It is available online without registration, with content in English and Polish, and the collection continues to expand.