It’s not about the pedigree. No, it has an esteemed history going back to 1828 as a menagerie for members of the Zoological Society of London. It’s just that it’s ultimately just a zoo, and a smallish one at that, with few large animals. A pair of Sumatran tigers arrived in 2013, but they’re not enough to justify the high-ticket price, especially for a first-time London visitor who could be learning about the city instead.