Le Clos Cristal was planted with Cabernet Franc and only some of the vines are trained through walls, the rest of the vineyard is planted normally. However, in the Clos des Murs at Parnay (part of the Château de Parnay) all the vines are trained through the walls. This is a much small vineyard and is planted with Chenin Blanc.
More details on Antoine Cristal:
Also Le Clos Cristal www.clos-cristal.com