Sometimes he is on foot but mostly he travels with a cart, the "Karrig an Ankou", drawn by two oxen and a lean horse. Two servants dressed in the same shroud and hat as the Ankou pile the dead into the cart, and to hear it creaking at night means you have little time left to live. As official religious statistics are forbidden in France, there are no official figures about religious practices in Brittany. However, successive polls show that the region tends to be more and more nonreligious. Catholic religion has started to decline after the Second World War, during the urbanisation of Brittany. A poll conducted in 2006 showed that Morbihan was the only "département" to have a strong Catholic population, around 70% of its inhabitants belonging to that religion. Loire-Atlantique and Côtes-d'Armor were among the least Catholic French "départements", with only 50% of Catholics, while Ille-et-Vilaine and Finistère were at around 65%. Other religions are almost non-existent, apart from Islam which gathers between 1 and 3% of the inhabitants in Ille-et-Vilaine and Loire-Atlantique. Brittany is home to many megalithic monuments; the words "menhir" and "dolmen" come from the Breton language. The largest menhir alignments are the Carnac stones. Other major sites include the Barnenez cairn, the Locmariaquer megaliths, the Menhir de Champ-Dolent, the Mane Braz tumulus and the Gavrinis tomb. Monuments from the Roman period are rare, but include a large temple in Corseul and scarce ruins of villas and city walls in Rennes and Nantes. Brittany has a large number of medieval buildings. They include numerous Romanesque and French Gothic churches, usually built in local sandstone and granit, castles and half-timbered houses visible in villages, towns and cities. Several Breton towns still have their medieval walls, such as Guérande, Concarneau, Saint-Malo, Vannes, Fougères and Dinan. Major churches include Saint-Pol-de-Léon Cathedral, Tréguier Cathedral, Dol Cathedral, Nantes Cathedral and the Kreisker chapel. Most of the Breton castles were rebuilt between the 13th and the 15th century, such as the Château de Suscinio, the Château de Dinan, the Château de Combourg, the Château de Largoët, the Château de Tonquédec, the Josselin Castle and the Château de Trécesson.