I've also fed all the way up Snowdon by train - it's particularly tricky if you're facing downhill, but fortunately another passenger noticed and swopped with me so that I was facing uphill.
While getting a massage in an automatic massage chair in the middle of Brent Cross.
Walking around Costco.
Both my children had their first outdoor feeds in Kew Gardens (nothing strange about that, but I liked it).
My weirdest place was sitting on a railing in front of Buckingham Palace during the Changing of the Guards - and the only time that I have ever had passers-by craning their heads around trying to see into my top!