Chartreuse du Mont-Dieu
Carthusian monastery located in Ardennes, in France.
Each edition grades its towns against each other only.

Of the 6 places to visit in and around Sy, 4 are châteaux or heritage sites. Sy itself has none of them. Day-trippers head 22 km out to Château de Sedan.
Close behind Chartreuse du Mont-Dieu are 2 châteaux, 2 attractions and a fort.
Best known first: by how many Wikipedia and sister-site articles cover each place (Wikidata’s count). It isn’t a ranking of how good they are.
Of the 6 nearby, most are to the north.
The first 20 on the list, numbered as below. The shape is the commune of Sy; the orange dot is its centre. © OpenStreetMap contributors · commune boundary: IGN
The two biggest groups: châteaux or heritage sites (4) and other sights (2).
Dark: in Sy. Light: in the communes within 5 km of its centre.
Its 6 places all lie within 5 km of its centre.
Carthusian monastery located in Ardennes, in France.
Church located in Ardennes, in France.
Nothing is mapped in Sy itself; these are within 5 km of its centre.
Leading the 12 is Château de Sedan, 22 km away; they include 3 attractions and 3 gardens.
ChâteauChâteau de Sedan22 km north, in SedanAttractionAttractionSNCF BB 1200021 km north, in Nouvion-sur-MeuseChâteauChâteauChâteau de Landreville18 km southeast, in BayonvilleGardenGardenArboretum de Vendresse12 km northwest, in VendresseAttractionAttractionPlace Ducale31 km north, in Charleville-MézièresMuseumMuseumOuvrage de La Ferté27 km east, in VillyGardenGardenJardin botanique de Sedan21 km north, in SedanAttractionAttractionMonument américain de Montfaucon33 km southeast, in Montfaucon-d'ArgonneFortFortFort des Ayvelles25 km north, in Villers-SemeuseGardenGardenArboretum du Petit-Bois33 km southeast, in Montfaucon-d'ArgonneFortFortOuvrage du Chesnois34 km east, in Thonne-le-ThilFortFortOuvrage de Thonnelle38 km east, in MontmédyPlaces within 40 km of Sy with an article in both French and English Wikipedia, nearest first.
Nothing is mapped in Sy itself, but within 5 km there are Chartreuse du Mont-Dieu, Église Saint-Martin de Tannay, Château de La Berlière and Château-ferme de Brieulles-sur-Bar.
No museum or gallery is mapped in Sy or within 5 km.
The nearest with articles in both French and English Wikipedia: Château de Sedan (22 km), SNCF BB 12000 (21 km), Château de Landreville (18 km), Arboretum de Vendresse (12 km).
From OpenStreetMap and Wikidata: named museums, galleries, châteaux, abbeys, gardens, zoos, theme parks and other visitor attractions whose mapped point lies inside the commune of Sy, then those in the communes within 5 km of its centre, and well-known places within 40 km. Houses, ruins and gardens need a sign they’re open to visitors; places marked private, closed or disused are left out. The historic-monument link is the Culture ministry’s Mérimée record. A place that isn’t mapped isn’t listed, so this isn’t everything there is to see.
Sources: OpenStreetMap (© OpenStreetMap contributors, ODbL), Wikidata (CC0: descriptions, websites, Wikipedia articles), the Culture ministry’s Mérimée database (Licence Ouverte 2.0), IGN commune boundaries. Distances are from the commune’s centre point.
Photos from Wikimedia Commons, each under its own licence (our copy, resized).
Contains public sector information under the Licence Ouverte / Open Licence 2.0 (Etalab): INSEE, DGFiP, the Interior Ministry’s statistics service (SSMSI), the Ministry of Education (DEPP), the Health Ministry’s statistics service (DREES) and the Housing Ministry (Carte des loyers). Commune boundaries: IGN Admin Express.