This isn't Londoner Pom du Cap writes:
Cleopatra's needle is a well known landmark on the north bank of the Thames near the Embankment tube station. What is less well known is how it got its name. Some speculate that it is because of its pointed shape, but the truth is more interesting. The obelisk was presented as a gift to London in the 19th century by the rulers of Egypt, who were less than impressed with Britain's foreign policies of the time. They decided to get their own back in two ways. The first was to make a great show of presenting the monument to the British High Commissioner in Egypt, but then to make it Britain's problem to get the thing back to these shores. The transport by boat, and the subsequent erection took months, cost the British authorities a small fortune, and produced no end of problems. The second thing the Egyptians did was to cover the needle in hieroglyphics, which of course the Londoners could not read. Years later it transpired that the etchings translated as rude jibes at Queen Victoria, and the British in general.
When this story got out, the Londoners started to refer to the monument as "Cleopatra's Needle". The Egyptian queen had of course been dead for a while by this stage, but the combination of her name and the word "needle", taken colloquially to mean wind up or irritate just seemed to fit, and the name stuck.