I listened to it today, and agree with Jim. I think it was the first radio programme I've listened to since the 1960s, and if this is a typical example I'll wait another 50 years before repeating it. The most interesting part was a couple of sentences in the last 9 minutes (I was clock watching to see how much more I had to endure just in case there were gems in the dungheap).
I couldn't see (literally and figuratively) why it was necessary to go to Avebury to have someone say that this (unseen) object is a 10x8 camera; and I don't think we needed to know that the presenter was popping back to his car to get an umbrella...