Fort Hoofddijk is the location where paleomagnetic research is conducted at Utrecht University. The Fort is located inside the botanical gardens, far away from any moving metal constructions. The fortification was used in 19th and 20th century as ammunition storage in the ‘Dutch Water Defence Lines’. To prevent explosion hazard by accidently creating a spark inside the building, no iron has been used during its construction.
This lack of iron enables us today to perform high quality palaeomagnetic experiments within the two shielded rooms available in the Fort.