FULL DETAILS TO FOLLOW
The festival is actually to east of Biarritz at the Chateau de Bellocq. You can see the location using the link below.
https://www.google.com/maps/place/43%C2%B031’05.6%22N+0%C2%B054’54.2%22W/@43.518229,-0.915062,757m/data=!3m2!1e3!4b1!4m4!3m3!8m2!3d43.518229!4d-0.915062?entry=ttu&g_ep=EgoyMDI1MDUwNS4wIKXMDSoASAFQAw%3D%3D