Abbaye Saint-Eusèbe de Saignon
Abbey located in Vaucluse, in France.
Each edition grades its towns against each other only.

There is no place to visit in Castellet-en-Luberon; there are 3 within 5 km of its centre. The mix takes in a monastery, a garden and an attraction. Make a day of it at Cathédrale Sainte-Anne d'Apt, 7.9 km away.
The rest of the best known are a garden and an attraction.
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.
To the northwest lie most of the 3 nearby.
The first 20 on the list, numbered as below. The shape is the commune of Castellet-en-Luberon; the orange dot is its centre. © OpenStreetMap contributors · commune boundary: IGN
It comes down to a monastery, a garden and an attraction.
Dark: in Castellet-en-Luberon. Light: in the communes within 5 km of its centre.
Look within 5 km of its centre for all 3.
Nothing is mapped in Castellet-en-Luberon itself; these are within 5 km of its centre.
The history of Castellet-en-Luberon → · Parks and trails in Castellet-en-Luberon →
Cathédrale Sainte-Anne d'Apt, 7.9 km away, is the best known of the 12.
CathedralCathédrale Sainte-Anne d'Apt7.9 km northwest, in AptAttractionAttractionAbbaye Notre-Dame de Sénanque26 km west, in GordesAttractionAttractionExsurgence de Fontaine-de-Vaucluse29 km west, in Fontaine-de-Vaucluse
CathedralCathédrale Saint-Sauveur d'Aix-en-Provence35 km south, in Aix-en-ProvenceAttractionAttractionChâteau de Lourmarin13 km southwest, in Lourmarin
MuseumMusée Granet35 km south, in Aix-en-ProvenceAttractionAttractionAbbaye Notre-Dame de Ganagobie38 km northeast, in Ganagobie
Archaeological siteOppidum d'Entremont32 km south, in Aix-en-ProvenceArt galleryArt galleryChâteau de Lacoste17 km west, in LacosteMuseumMuseumVillage des bories25 km west, in GordesAttractionAttractionAqueduc de Roquefavour39 km south, in VentabrenCathedralCathedralConcathédrale Notre-Dame-du-Bourguet de Forcalquier27 km northeast, in ForcalquierPlaces within 40 km of Castellet-en-Luberon with an article in both French and English Wikipedia, nearest first.
Nothing is mapped in Castellet-en-Luberon itself, but within 5 km there are Abbaye Saint-Eusèbe de Saignon, Potager d'un Curieux and Borie.
No museum or gallery is mapped in Castellet-en-Luberon or within 5 km.
The nearest with articles in both French and English Wikipedia: Cathédrale Sainte-Anne d'Apt (7.9 km), Abbaye Notre-Dame de Sénanque (26 km), Exsurgence de Fontaine-de-Vaucluse (29 km), Cathédrale Saint-Sauveur d'Aix-en-Provence (35 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 Castellet-en-Luberon, 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.