Peel Castle was originally constructed by Vikings. The castle stands on St Patrick's Isle which is connected to the town by a causeway. It is open to visitors during the summer.
The castle was built in the 11th century by the Vikings, under the rule of King Magnus Barefoot. While there were older stone Celtic monastic buildings on the island, the first Viking fortifications were built of wood. The prominent round tower was originally part of the Celtic monastery, but had battlements added at a later date. In the early 14th century, the majority of the walls and towers were built primarily from local red sandstone, which is found abundantly in the area. After the rule of the Vikings, the castle continued to be used by the Church due to the cathedral built there – the see of the diocese of Sodor and Man – but was eventually abandoned in the 18th century.
The castle remained fortified, and new defensive positions were added as late as 1860. The buildings within the castle are now mostly ruined, but the outer walls remain intact. Excavations in 1982-87 revealed an extensive graveyard as well as the remains of Magnus Barefoot's original wooden fort. The most spectacular finds were the 10th century grave of 'The Pagan Lady' which included a fine example of a Viking necklace and a cache of silver coins dating from about 1030. The Castle's most famous 'resident' is the so-called Moddey Dhoo or 'Black Dog' ghost.
The Abbey of Saint-Etienne, also known as Abbaye aux Hommes ('Men"s Abbey'), is a former monastery dedicated to Saint Stephen (Saint Étienne). It is considered, along with the neighbouring Abbaye aux Dames ('Ladies" Abbey'), to be one of the most notable Romanesque buildings in Normandy. Like all the major abbeys in Normandy, it was Benedictine.
Lanfranc, before being an Archbishop of Canterbury, was abbot of Saint-Etienne. Built in Caen stone during the 11th century, the two semi-completed churches stood for many decades in competition. An important feature added to both churches in about 1120 was the ribbed vault, used for the first time in France. The two abbey churches are considered forerunners of the Gothic architecture. The original Romanesque apse was replaced in 1166 by an early Gothic chevet, complete with rosette windows and flying buttresses. Nine towers and spires were added in the 13th century. The interior vaulting shows a similar progression, beginning with early sexpartite vaulting (using circular ribs) in the nave and progressing to quadipartite vaults (using pointed ribs) in the sanctuary.
The two monasteries were finally donated by William the Conqueror and his wife, Matilda of Flanders, as penalty for their marriage against the Pope"s ruling. William was buried here; Matilda was buried in the Abbaye aux Dames. Unfortunately William"s original tombstone of black marble, the same kind as Matilda"s in the Abbaye aux Dames, was destroyed by the Calvinist iconoclasts in the 16th century and his bones scattered.
As a consequence of the Wars of Religion, the high lantern tower in the middle of the church collapsed and was never rebuilt. The Benedictine abbey was suppressed during the French Revolution and the abbey church became a parish church. From 1804 to 1961, the abbey buildings accommodated a prestigious high school, the Lycée Malherbe. During the Normandy Landings in 1944, inhabitants of Caen found refuge in the church; on the rooftop there was a red cross, made with blood on a sheet, to show that it was a hospital (to avoid bombings).