Châteaux of the 18th century
Oostergeest
Teylingen — Netherlands — XVII–XIX
Oostergeest is a château at Teylingen, Zuid-Holland, in the Netherlands. The recorded building campaigns date from the 17th, 18th and 19th centuries. Its architecture is recorded as Hollands Classicisme. The register records it as “rijksmonument”. Details are drawn from Rijksmonumentenregister.

Oosterhout
Haarlem — Netherlands — XVIII–XIX
Oosterhout is a château at Haarlem, Noord-Holland, in the Netherlands. The recorded building campaigns date from the 18th and 19th centuries. The register records it as “rijksmonument”. Details are drawn from Rijksmonumentenregister.

Oostermeer
Amstelveen — Netherlands — XIV–XVIII
Oostermeer is a château at Amstelveen, Noord-Holland, in the Netherlands. The recorded building campaigns date from the 14th and 18th centuries. Its architecture is recorded as Lodewijk XIV-stijl. The register records it as “rijksmonument”. Details are drawn from Rijksmonumentenregister.

Orangerie du château de Montmorency
Montmorency · Val-d’Oise — France — XVIII–XIX
Orangerie du château de Montmorency is a château at Montmorency, Val-d'Oise, in the Île-de-France region of France. The recorded building campaigns date from the 18th and 19th centuries. It is protected as a monument historique at the second level (inscrit). Details are drawn from the Base Mérimée of the French Ministry of Culture.

Ormesby Hall
Redcar and Cleveland — United Kingdom — XVIII
Ormesby Hall is a château at Redcar and Cleveland, England, in the United Kingdom. The recorded building campaign dates from the 18th century. The register records it as “Grade I listed building”. Details are drawn from Wikidata.
- XVIII
Osteria della Cartiera
Faenza · Papal States — Italy — XVIII
Osteria della Cartiera is a château at Faenza, Emilia-Romagna, in Italy. The recorded building campaign dates from the 18th century. The register records it as “Italian national heritage”. Details are drawn from Wikidata.

Ostermundigengut (1707)
Ostermundigen — Switzerland — XVIII
Ostermundigengut (1707) is a château at Ostermundigen, in Switzerland. The recorded building campaign dates from the 18th century. The register records it as “Swiss cultural property of cantonal or local significance”. Details are drawn from Wikidata.
- XVIII
Östliches Herrenhaus (Einzeldenkmal zu ID-Nr. 09303938) Jan-Kilian-Straße 6
Weißenberg · Bautzen District — Germany — XVIII
Östliches Herrenhaus (Einzeldenkmal zu ID-Nr. 09303938) Jan-Kilian-Straße 6 is a château at Weißenberg, Saxony, in Germany. The recorded building campaign dates from the 18th century. The register records it as “heritage monument in Saxony”. Details are drawn from Wikidata.

Oud Amelisweerd
Bunnik — Netherlands — XV–XX
Oud Amelisweerd is a château at Bunnik, Utrecht, in the Netherlands. The recorded building campaigns date from the 15th, 16th, 18th, 19th and 20th centuries. Its architecture is recorded as n.v.t.. The register records it as “rijksmonument”. Details are drawn from Rijksmonumentenregister.

Oud-Bussem
Huizen — Netherlands — XVII–XVIII
Oud-Bussem is a château at Huizen, Noord-Holland, in the Netherlands. The recorded building campaigns date from the 17th and 18th centuries. Its architecture is recorded as Nieuw-Historiserende stijl. The register records it as “rijksmonument”. Details are drawn from Rijksmonumentenregister.

Over Holland
Stichtse Vecht — Netherlands — XV–XXI
Over Holland is a château at Stichtse Vecht, Utrecht, in the Netherlands. The recorded building campaigns date from the 15th, 17th, 18th, 19th, 20th and 21st centuries. Its architecture is recorded as n.v.t.. The register records it as “rijksmonument”. Details are drawn from Rijksmonumentenregister.

Painswick House
Painswick · South West England — United Kingdom — XVIII
Painswick House is a château at Painswick, in the United Kingdom. The recorded building campaign dates from the 18th century. The register records it as “Grade I listed building”. Details are drawn from Wikidata.

Palacete na Rua Passos Manuel
União de Freguesias da Cidade de Santarém — Portugal — XVIII
Palacete na Rua Passos Manuel is a château at União de Freguesias da Cidade de Santarém, Santarém, in Portugal. The recorded building campaign dates from the 18th century. The register records it as “Included in protected site”. Details are drawn from Wikidata.

Palacete na Rua Serpa Pinto
Vila Franca de Xira — Portugal — XVIII
Palacete na Rua Serpa Pinto is a château at Vila Franca de Xira, Lisbon, in Portugal. The recorded building campaign dates from the 18th century. The register records it as “heritage without legal protection”. Details are drawn from Wikidata.

Palacete romântico da família Caldas
União de Freguesias da Cidade de Santarém — Portugal — XVIII
Palacete romântico da família Caldas is a château at União de Freguesias da Cidade de Santarém, Santarém, in Portugal. The recorded building campaign dates from the 18th century. The register records it as “heritage without legal protection”. Details are drawn from Wikidata.

Palacio Bauer
Universidad — Spain — XVIII
Palacio Bauer is a château at Universidad, Community of Madrid, in Spain. The recorded building campaign dates from the 18th century. Its architecture is recorded as baroque architecture. The register records it as “bien de interés cultural”. Details are drawn from Wikidata.

Palacio de los Duques de Osuna
Aranjuez — Spain — XVIII
Palacio de los Duques de Osuna is a château at Aranjuez, Community of Madrid, in Spain. The recorded building campaign dates from the 18th century. Its architecture is recorded as Neoclassical architecture. The register records it as “Red List of Endangered Heritage item”. Details are drawn from Wikidata.

Palais Büeler
Schwyz — Switzerland — XVIII
Palais Büeler is a château at Schwyz, Schwyz, in Switzerland. The recorded building campaign dates from the 18th century. The register records it as “class A Swiss cultural property of national significance”. Details are drawn from Wikidata.

Palais de Compiègne et ses abords
Compiègne · Oise — France — XVIII–XIX
Palais de Compiègne et ses abords is a château at Compiègne, Oise, in the Hauts-de-France region of France. The recorded building campaigns date from the 18th and 19th centuries. Its architecture is recorded as baroque architecture. It is protected as a monument historique at the higher of the two levels (classé). Details are drawn from the Base Mérimée of the French Ministry of Culture.
Palais Holnstein
Munich · Upper Bavaria — Germany — XVIII
Palais Holnstein is a château at Munich, Bavaria, in Germany. The recorded building campaign dates from the 18th century. Its architecture is recorded as baroque architecture. The register records it as “architectural heritage monument in Bavaria”. Details are drawn from Wikidata.

Palais Rastede
Rastede · Ammerland District — Germany — XVIII
Palais Rastede is a château at Rastede, Lower Saxony, in Germany. The recorded building campaign dates from the 18th century. Its architecture is recorded as historicist architecture. The register records it as “Kulturdenkmal”. Details are drawn from Wikidata.

Palazzo Landi
Alseno — Italy — XVIII
Palazzo Landi is a château at Alseno, Emilia-Romagna, in Italy. The recorded building campaign dates from the 18th century. The register records it as “Italian national heritage”. Details are drawn from Wikidata.
Pavillon de Grennevile
Crasville · Manche — France — XV–XVIII
Pavillon de Grennevile is a manor house at Crasville, Manche, in the Normandie region of France. The recorded building campaigns date from the 15th, 17th and 18th centuries. It is protected as a monument historique at the second level (inscrit). Details are drawn from the Base Mérimée of the French Ministry of Culture.
- XVI–XIX
Pavillon dit des Ducs
Buzançais · Indre — France — XVI–XIX
Pavillon dit des Ducs is a château at Buzançais, Indre, in the Centre-Val de Loire region of France. The recorded building campaigns date from the 16th, 18th and 19th centuries. It is protected as a monument historique at the second level (inscrit). Details are drawn from the Base Mérimée of the French Ministry of Culture.