April 28 is a special day for Salisbury Cathedral as it marks the day construction of the cathedral began in 1220. The cathedral’s spire, at 404 feet (123 m), is the tallest in England. Salisbury also holds one of the four surviving original copies of Magna Carta. It is also the place where the ashes of former British Prime, Edward Heath are interred. The Cathedral clock, which dates from about 1386, is supposedly the oldest working modern clock in the world.