SGM335076: Albi Cathedral (photo) / Bridgeman Images

HGP362472: Norman Tower, Norwich Cathedral (photo) / Bridgeman Images

CLF310413: Traquair House, a view of the forecourt from the avenue, from '100 Favourite Houses' (b/w photo), English Photographer, (20th century) / Bridgeman Images

XPH311125: Burg Stolpen, built in c.1100 (photo) / Bridgeman Images

VLS938014: Palazzo Communale, Massa Marittima (photo) / Bridgeman Images

STF810491: Cologne cathedral, main portal of the west facade, Cologne, Germany (photo) / Bridgeman Images

SAP490631: Rose window, Cathedral of Saint Beningus, Dijon, France (photo) / Bridgeman Images

TRK2637105: Sart Rib vault, New Cathedral, Salamanca, Castile and Leon, Spain (photo) / Bridgeman Images

TRK2597941: Gothic cathedral, 13th-14th centuries, Facade, Leon, Spain / Bridgeman Images

LLM2793598: Ravenscraig Castle (engraving), English School, (19th century) / Bridgeman Images

IBE5341946: Interior view of the cathedral (duomo) (1059-1117) from Parma, Italy (photo) / Bridgeman Images

RWJ448005: Medieval buildings in Romerberg Square, Frankfurt am Main (photo) / Bridgeman Images

SZT5978821: Cathedral of St Peter, Regensburg, 16th century (photo) / Bridgeman Images

MUC176348: Aerial view Monteriggioni, Tuscany, Italy (photo) / Bridgeman Images

KW6267042: Bridge at Cangas de Onis, Asturias, Spain, 2016 (photo) / Bridgeman Images

XPC341178: West rose window, 1385-92 (photo) / Bridgeman Images

KWE268366: Bridge, gateway and Cathedral of Burgos, illustration from 'Spanish Pictures' by the Rev. Samuel Manning (engraving), English School, (19th century) / Bridgeman Images

HGP362536: Orford Castle (photo) / Bridgeman Images

STF696222: Ulm Minster, Germany (photo) / Bridgeman Images

STF452299: View of a Byzantine building, probably a hospital, Side, Turkey (photo) / Bridgeman Images

TMA396207: Rievaulx Abbey, Yorkshire (b/w photo) / Bridgeman Images

MAE3469548: Church of Saint Anne of Nohant, Nohant-Vic, Centre, Indre, France (photo) / Bridgeman Images

LLM3096603: York Minster (b/w photo), English Photographer, (20th century) / Bridgeman Images

IBE5339106: The wheel at dawn (or the noria) of the mill of the Albolafia (1136-1137), on the river Guadalquivir, Cordoba (Spain). / Bridgeman Images

IBE5335884: View of the frescoes. 12th century Pantheon of the Royal College of St. Isidoro (Royal College of St. Isidoro), Leon. / Bridgeman Images

SCN3249127: View of the Lutheran Cathedral, Tromso, Norway (photo) / Bridgeman Images

SCN3249133: View of the Lutheran Cathedral, Tromso, Norway (photo) / Bridgeman Images

WOL3872972: Carcassonne / Bridgeman Images

WOL3872975: Carcassonne / Bridgeman Images

SZT5978835: Aerial view of the Cathedral of Sts Maurice and Catherine, Magdeburg, 1209-1520 (photo) / Bridgeman Images

KW6267043: Bridge at Cangas de Onis, Asturias, Spain, 2016 (photo) / Bridgeman Images

POV1076976: Mehrangarh Fort on rocky hill behind Jaswant Thada above the Old City at sunrise, Jodhpur (The Blue City), Rajasthan, India / Bridgeman Images

ELC434091: The Effects of Good Government in the City, 1338-40 (fresco) Effects of Good Government, c.1338 (fresco) (detail of 434090), Lorenzetti, Ambrogio (1285-c.1348) / Bridgeman Images

XPC341116: North transept (photo) / Bridgeman Images

XJF937987: View of Rochester Castle, Kent. c.1830 (engraving), English School, (19th century) / Bridgeman Images

NUM1076482: Ramparts, towers and gates, Aigues Mortes, France (photo) / Bridgeman Images