Cathédrale Notre Dame de Chartres

The 130m-long Cathédrale Notre Dame de Chartres, one of the crowning architectural achievements of Western civilisation, was built in the Gothic style during the first quarter of the 13th century to replace a Romanesque cathedral that had been devastated by fire – along with much of the town – in 1194. Because of effective fund-raising and donated labour, construction took only 30 years, resulting in a high degree of architectural unity. It is France's best-preserved medieval cathedral, having been spared postmedieval modifications, the ravages of war and the Reign of Terror.

The cathedral's west, north and south entrances have superbly ornamented triple portals, but the west entrance, known as the Portail Royal, is the only one that predates the fire. Carved from 1145 to 1155, its superb statues, whose features are elongated in the Romanesque style, represent the glory of Christ in the centre, and the Nativity and the Ascension to the right and left, respectively. The structure's other main Romanesque feature is the 105m-high Clocher Vieux (Old Bell Tower; also called the Tour Sud or 'South Tower'), which was begun in the 1140s. It is the tallest Romanesque steeple still standing anywhere.

A visit to the 112m-high Clocher Neuf (New Bell Tower), also known as the Tour Nord (North Tower), is worth the ticket price and the climb up the long spiral stairway (350 steps). Access is just behind the cathedral bookshop. A 70m-high platform on the lacy Flamboyant Gothic spire, built from 1507 to 1513 by Jehan de Beauce after an earlier wooden spire burned down, affords superb views of the three-tiered flying buttresses and the 19th-century copper roof, turned green by verdigris.

The cathedral's 172 extraordinary stained-glass windows, almost all of which date back to the 13th century, form one of the most important ensembles of medieval stained glass in the world. The three most exquisite windows, dating from the mid-12th century, are in the wall above the west entrance and below the rose window. Survivors of the fire of 1194 (they were made some four decades before), the windows are renowned for the depth and intensity of their blue tones, famously called 'Chartres blue'.

The cathedral's 110m crypt , a tombless Romanesque structure built in 1024 around a 9th-century predecessor, is the largest in France. Tours in French (with a written English translation) lasting 30 minutes start at La Crypte, the cathedral-run shop selling souvenirs, from April to October. At other times they begin at the shop below the Clocher Neuf in the cathedral.

The shop also rents informative English-language audioguide tours (25/45/70min €3.20/4.20/6.20) – you'll need to leave your passport or other ID as a deposit. Guided tours in English with the incomparable Malcolm Miller depart from the shop.