[azepoi]

There are loads of bastion fortresses in France thanks to this guy: https://en.wikipedia.org/wiki/Sébastien_Le_Prestre_de_Vauban

[cataflam]

For some great examples, in pictures: https://duckduckgo.com/?q=vauban+citadelle&iar=images&iax=im...

[pryelluw]

Those remind me of the anime Attack on Titan.