There are a lot of castles in France, but not all are open to visit. I have made an extensive list of castles in the region. So if you are touring in Charente and come across a château you can easily see if it is open for public or not. If you are still at home, you can use the list for preparing your holiday.
All the castles are also presented on the map: activate the layer with castles and de-activate the layer with brands and producers to make it easier to differentiate between all the pictograms on the map.

Roche-Courbon castle

Table with castles:

Locationname of castleOpen voor visits 
Angeac-ChampagneChateau de Roissacno
ArsChateau d'Arsno
Balzac Chateau de Balzac yes
Barbezieux-Saint-HilaireChateau de Barbezieuxyes
BarbézièresChateau de Barbézièresyes
BonneuilChateau de Breuilno
BoutevilleChateau de Boutevilleyeslimited
ChalaisChateau de Chalaisyes
Cherves-RichemontChateau de Chesnelyescognac producer
ChevanceauxChateau de Chauxno
ChillacChateau de Chillacno
CrazannesChateau de Crazannesyes
Dampierre-sur-BoutonneChateau de Dampierre-sur-Boutonneyes
DeviatChateau de la Fayeno
Douhet Chateau du Douhet yes (L)only on appointment; haunted!
Ecoyeux Chateau de Ecoyeux (=Ch de Polignac) no
EcuratChateau de Morinerieno
GeayChateau de Geayno
GémozacChateau de Bernessard no
Isle d’OleronChateau de d’Oleronyes
JarnacChateau de Saint-Martialnoused to be owned by Bisquit and Dubouché
JonzacChateau de Jonzacyes (L)town hall; only now and then guided tours
Juillac-le-CoqChateau de Beauregardyescognac producer De lothérie
La CouronneChateau de l’Oisellerieyeslyceum; only distillerie open voor visiting
Lignières-SonnevilleChateau de Lignièresnotown hall
LussacChateau de Lussacyes (L)but seldom
Magnac-Lavalette-VillarsChateau de la Mercerie yes (L)arboretum is open; castle on some days
MathaChateau de Mathayes
MerignacChateau de Villars-Marangeno
MerpinsChateau de Merpinsnoruïns
MeuxChateau de Meuxyesin the summer
Montmoreau-St-CybardChateau de Montmoreaunoclosed for restauration
NersacChateau de Fleuracnoopen for groups above 15 people
Neuvicq-le-ChateauChateau de Neuvicqyesin the summer
NieulChateau de Nieulno
Nieul-les-SaintesChateau de Nieul-les-Saintesyesin the summer
NonacChateau de Léotardieno
PlassacChateau de Plassacyesalso distillery and cognac for sale
PonsDonjon de Ponsyes
PonsChateau d’Ussonyesadventure- parc
Port d’EnvauxChateau de Panloyyes
RiouxChateau de Riouxno
RochefoucauldChateau de Rochefoucauldyes
RouillacChateau de Lignièresnoowned by Martell; previously owned by Rémy Martin
RétaudChateau de Chatenetno
Saint-Amant-de-NouèreChateau de Fontguyonno
Saint-Brice Chateau de Saint-Brice noowned by Hennessy
Saint-Brice Chateau de Garde-Épéeno
Saint-Dizant-du-GuaChateau de Beaulonyes (L)cognac for sale and parc
Saint-Georges-des-CoteauxChateau de Romefortno
Saint-PorchaireChateau de Roche-courbon yesalso gardens to visit
Saint-SavinienChateau de Bernerayno
SoulignonneChateau de Ransannenoonly gardens are open
St-Jean-d’AngleChateau de St-Jean- d’Angleyesadventure-parc
St-Pierre-de-l’IsleChateau de Mornaynoonly gardens are open
SurgèresChateau de Surgèresyes (L)town hall
TaillebourgChateau de Taillebourgyes
TranchadeChateau de la TranchadenoHotel; on momuments days open for visits
Verteuil-sur-CharenteChateau de Verteuilnoparc; and kitchen on request
Villebois-LavaletteChateau de Villebois-Lavaletteyes
VillexavierChateau de la Fayeno