Biggest 'Cathedral' in the world

The One-Show with Adrien Chiles and visiting Monty Python celeb star, Michael Palin, was asked if he liked Canterbury Cathedral, said to be one of the largest in he world and he then said that the largest 'Cathedral' that he had visited was a mud mosque in Mali. Every year the mud walls were repaired by the members of the Muslim congregation in the town - It was the same Mosque as shown on Ruth and Julian's photos. Dad