https://web.archive.org/web/20031130162755/http://www.bezreg-detmold.nrw.de/Aufgaben/Organisation/Abteilung5/Dezernat51/Naturschutzgebiete/KreisLippe/Externsteine/index.html bezreg-detmold.nrw.de - "Nature Externsteine"] Today the preserve measures approximately 27 acres , and forms part of the ‘Teutoburg Forest’ nature reserve, Externsteine. [