Read this: Cork features architecturally notable buildings originating from the Medieval to Modern periods. The only notable remnant of the Medieval era is the Red Abbey. There are two cathedrals in the city; St. Mary's Cathedral and Saint Fin Barre's Cathedral. St Mary's Cathedral, often referred to as the North Cathedral, is the Catholic cathedral of the city and was begun in 1808. Its distinctive tower was added in the 1860s. St Fin Barre's Cathedral serves the Protestant faith and is possibly the more famous of the two. It is built on the foundations of an earlier cathedral. Work began in 1862 and ended in 1879 under the direction of architect William Burges.

When did work end on the Red Abbey under the direction of William Burges?
What is the answer? (If it cannot be answered, return "unanswerable")
unanswerable