Burgenwelt is a German-language online resource for people interested in medieval and early modern castles, fortifications, town walls, and other defensive structures. It presents more than 6,600 sites across 65 countries, with information compiled by the site team and contributing guest authors. The project describes itself as a popular educational resource created by castle enthusiasts, rather than a scholarly database, and provides its information and downloads free of charge.

Individual entries bring together concise background details, historical and architectural information, photographs, and, where available, plans or sketches. Visitors can also find practical guidance on location, access, opening hours, admission prices, and nearby food or accommodation. These features make the site useful for travellers weighing a visit, day-trippers searching by region, hikers planning stops, and readers researching particular fortifications. The website also offers search tools, literature references, reviews, links to further resources, and information about excursions. Burgenwelt welcomes contributions about sites visited by authors, helping expand and update its worldwide directory.