In the 2013 Christmas Special Carson twice mentions going to the Crystal Palace in its new location, once specifically mentioning Sydenham Hill. The Crystal Palace was first located in Hyde Park for one year (1851) for an exhibition, then permanently moved to the Sydenham Hill location, opening again in 1854.
By the early part of the 20th century it had fallen into neglect and disuse. It was renovated and got a second life in 1920, but was not moved. So it was last moved before Carson was even born and therefore an odd choice of words to refer to its new location. Did this big of an error slip past Alastair Bruce or is Carson referring to something else?