Such an interesting historic place right in the middle of Luxemburg. I was really impressed by the extent of the Casemates. If you’re interested in the history of this beautiful city, you really must visit this site. It only costs 4 euro per person and you get a feeling of how it must have been when people where using this place to defend the city. Be warned though, lots of narrow staircases and some places are really dark. Not for you if you are claustrophobic.

Information
Casemates du Bock
Montée de Clausen 10
Luxembourg City
Luxembourg
https://www.luxembourg-city.com/en/place/fortifications/bock-casemates
https://en.wikipedia.org/wiki/Bock_(Luxembourg)
http://www.visitluxembourg.com/en/place/castle/bock-casemates-luxembourg

Visited April 2015. You can find my review about Casemates du Bock also on TripAdvisor.