Christ Church Cathedral is Dublin’s oldest building. Dating from 1038, it was founded by Sitriuc, first Christian King of the Dublin Norsemen, but in 1172, Richard de Clare pulled it down and built a new cathedral, unfortunately, on a peat bog. In 1562 half this building collapsed, and what was left stood alone and decaying until the 1870s, when the cathedral was restored. Remnants of the 12th-century cathedral include the leaning north wall and the crypt, one of the largest in Ireland. The Exhibition, Treasures of Christ Church Cathedral, illustrates a millennium of worship and ecclesiastical architecture in Ireland.