I love this sign. I can't imagine anyone is in any real danger from vipères (adders), but the sign is stylish and adds a frisson to a visit to the château de Montpoupon.
This rocky ledge is at the base of the château perimeter wall, right on the roadside. I am sure no self respecting adder would be tempted to lay about here during visiting hours, no matter how enticingly warm the rock got. I bet the local adders love this place first thing in the morning though, when it allows them to refuel for a day of lurking about in the undergrowth, ready to strike unsuspecting voles.