Well one look at the filming locations will tell you that many of the scenes were filmed in England. The props department were likely British. The most obvious example of the movie being shot partially in England is the Metropolis subway scene when superman stops the runaway train. It was filmed in Aldwych Underground Station in London due to the fact that at the time of filming it only operated during week day peak hours. I find it hard to believe there wasn't some abandoned NY Subway station they could use while filming there, but there you go.
If you dip your foot into a pool of piranhas don't cry when you lose a toe!