Which cathedral has the world's oldest working clock and the best surviving of the four original copies of the Magna Carta?

Salisbury Cathedral, formally known as the Cathedral Church of the Blessed Virgin Mary, is an Anglican cathedral in Salisbury, England, and one of the leading examples of Early English architecture. The main body of the cathedral was completed in only 38 years, from 1220 to 1258.

Since 1549, the cathedral has had the tallest church spire in the United Kingdom, at 404 feet (123m). Visitors can take the "Tower Tour" where the interior of the hollow spire, with its ancient wood scaffolding, can be viewed. The cathedral also has the largest cloister and the largest cathedral close in Britain (80 acres). It contains the world's oldest working clock (from AD 1386) and has the best surviving of the four original copies of Magna Carta. In 2008, the cathedral celebrated the 750th anniversary of its consecration.

The cathedral is the mother church of the Diocese of Salisbury and is the seat of the Bishop of Salisbury, currently the Right Reverend Nick Holtam.