I first picked up this fascinating book by Peter Ackroyd because I thought it had something to do with the London “Underground,” otherwise known as its subway system. And indeed several parts of the book do concern the Underground. But the majority of the pages concern the vast array of other activities that go on under the streets of London, from sewers and springs to Roman ruins and excavated rooms. Whole rivers flow underneath London. The accounts of the building of the subway system were particularly interesting to me — and, I would like to think, to everyone. It’s not a deep work (no pun intended), but it’s an enjoyable way to learn about what’s going on beneath one of the world’s most important cities…not to mention its subway system!