- staypoland.com about_poznan.htm/The city experienced intense industrial growth and became an important military centre for Prussia, known as Festung Posen (Fortress Poznan).
- quizquizgo.com map/124322-where-is-poznan-fortressWhere is Poznań Fortress? Coordinates: 16.9352 52.4219. Show larger map.
- ru.wikibrief.org wiki/Poznań_FortressO 40fikacjach miasta Poznania w XIX i XX wieku., Познань 2006, Wydawnictwo Rawelin, ISBN 83-915340-2-2.
- its-poland.com attraction/poznan-fortress-daysPoznań Fortress Days is an annual event organized by the Poznań Local Tourist Organization together with partners.
- wikijtr.icu wiki/Poznań_FortressPoznań Kalesi - Poznań Fortress. Katedral Kilidinin Kalıntıları (Dom Schleuse), orijinal iç savunma halkasının bir parçası.
- commons.wikimedia.org wiki/Category:Twierdza_…...Poznańs festning; Vesting Poznań; forteresse de Poznań; Тврђава Познањ; Fortaleza de Poznań; Poznańin linnoitus; Poznań Fortress; Poznań Fortress
- webarchive.library.unt.edu web/20201218211023/…Due to its strategic location, the Prussian authorities intended to make Poznań into a fortress city, building a ring of defensive fortifications around it.
- dvidshub.net news/337192/7th-poznan-fortress-daysThis is the seventh annual celebration of Poznan Fortress Days, which occurred on August 24- 25 and highlighted over 20 different locations and attractions...
- wblog.wiki nn/Poznań_FortressPoznań Fortress, known in German as Festung Posen (Polish: Twierdza Poznań) was a set of fortifications in the city of Poznań (German: Posen) in western...