A word to describe Vauban's structures would be 'massive'. The defensive works all appear on a grand scale. But of the 12 locations forming this WHS, only the one at Longwy has been put to the test. The locations that I have visited are :
Neuf Brisach - huge fortifications, huge square and a huge red church (bus from Colmar)
Besancon - Fort Griffen (near the station) and Citadelle (free navette from Parking Chamars)
Briancon - steep streets within massive walls, with several entrance gates (train from Gap then bus #1 to Champ de Mars)
Mont Dauphin - steep hike from Mont Dauphin station (train from Gap)
Villefranche de Conflent - steep climb up to Fort Liberia through a tunnel in the cliff (train from Perpignan)
Mont Louis - fort with steep streets overlooking the Pyrenees (Petit Train Jaune to La Cabanasse)
Fort Medoc/Pate Island/Blaye - three forts on the Gironde river (train to Moulis-Listrac, bus to Cussak or Blaye, or ferry from Blaye to Lamarque)
Ile de Rey - sea walls and fortifications, citadelle occupied by the Militaire (bus from La Rochelle)
Camaret sur Mer - tower at the harbour entrance (bus from Quimper or Brest)
St Vaast La Hogue - fort on Tatihou Island and tower at La Hogue (bus from Cherbourg or Valognes, ferry to the island)
Longwy - massive fort forming the Upper Town, with ramparts, bastions and portals (train from Rheims or Luxembourg, navette to the Upper Town - except Sundays)
Arras - small fort in the city, occupied by the Militaire.
(Arras is also home to some monumental war cemeteries, and the Museum of the Company of New Zealand Tunnelers at the Wellington Quarry).