The Defense Business District like...
Abbey Jumièges is an incredible site, both because no roof ruin is present, but with important elements intact towers, facades and walls, it offers an incredible look. A majestic site.
Royaumont Abbey is located in the Val d'Oise, it is one of the largest abbey in the Paris region. A haven to visit.
The abbey of Vaux-de-Cernay is a former Cistercian monastery, both in ruins and preserved, it is located in Chevreuse Valley in a beautiful park.