History of Fort Hoofddijk

Fort Hoofddijk was built in 1879 as one of the fortifications around Utrecht that formed part of the Nieuwe Hollandse Waterlinie, or 'New Dutch waterline'. 

This defense line made use of inundating parts of Holland to stop the advance of the enemy, but because Utrecht was on relatively high ground, it needed an additional ring of fortifications.

 Wikipedia: Dutch Waterline (en)

Wikipedia: Nieuwe Hollandse Waterlinie (nl)

www.hollandsewaterlinie.nl (nl)

City of Utrecht Homepage (new window)
Photo courtesy of Douwe van Hinsbergen
Botanical garden Housed in a historical bunker in the middle of the Utrecht University Botanical gardens , it sports a variety of instruments to investigate the magnetisation of earth material (mostly rocks). 
(Photo: Ingeborg van Oorschot) 
The Fort building is excellently suited for rock magnetic and paleomagnetic research, partly because it is not very sensitive to mechanical disturbance (vibrations) and temperature fluctuations. The Fort is entirely built from bricks, providing a magnetically very quiet environment.
Fort Hoofddijk
In the front of the building are offices, a chemical lab, a ‘cantine’ for coffeebreaks and lunch, and a magnetically shielded room. (Photo: Ingeborg van Oorschot) 
AF demagnetising coil up to 300 mT In the former gunpowder storage rooms - where there is no iron or steel because of spark danger - much of the lab equipment is found. 

One of the 'Remises' serves as the sample preparation room.