Altissimo Nantes on Clmb House. Venue in 3 Rue Louis Blanc, 44230 Saint-Sébastien-sur-Loire, France, France. Altissimo Nantes, the network's tenth hall, opened in December 2013, offers 1,200 m² of climbing surface with 59 belay points, 12.5 m height, and an overhang...