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.
Castle Rushen is located in the Isle of Man"s historic capital, Castletown. The castle is amongst the best examples of medieval castles in the British Isles, and is still in use as a court house, museum and educational centre.
The exact date of castle is unknown, although construction is thought to have taken place during the reigns of the late 12th century and early 13th century rulers of the Isle of Man – the Kings of Mann and the Isles. The original Castle Rushen consisted of a central square stone tower, or keep. The site was also fortified to guard the entrance to the Silver Burn. From its early beginnings, the castle was continually developed by successive rulers of Mann between the 13th and 16th century. The limestone walls dominated much of the surrounding landscape, serving as a point of dominance for the various rulers of the Isle of Man. By 1313, the original keep had been reinforced with towers to the west and south. In the 14th century, an east tower, gatehouses, and curtain wall were added.
After several more changes of hands the English and their supporters eventually prevailed. The English king Edward I Longshanks claimed that the island had belonged to the Kings of England for generations and he was merely reasserting their rightful claim to the Isle of Man.
The 18th century saw the castle in steady decay. By the end of the century it was converted into a prison. Even though the castle was in continuous use as a prison, the decline continued until the turn of the 20th century, when it was restored under the oversight of the Lieutenant Governor, George Somerset, 3rd Baron Raglan. Following the restoration work, and the completion of the purpose-built Victoria Road Prison in 1891, the castle was transferred from the British Crown to the Isle of Man Government in 1929.
Today it is run as a museum by Manx National Heritage, depicting the history of the Kings and Lords of Mann. Most rooms are open to the public during the opening season (March to October), and all open rooms have signs telling their stories. The exhibitions include a working medieval kitchen where authentic period food is prepared on special occasions and re-enactments of various aspects of medieval life are held on a regular basis, with particular emphasis on educating the local children about their history. Archaeological finds made during excavations in the 1980s are displayed and used as learning tools for visitors.