Obelisk is an ancient Egyptian pillar made of red granite with rectangular base tapering to a pyramidal top. These pillars depict religious hieroglyphics.
The inscription at the base of the obelisk says that the Pharaoh Thothmes III erected it in Heliopolis, (Sun City, which is one of the oldest Egyptian cities) around 1500 BC. Two centuries later Rameses added lateral inscriptions. During the Greek Dynasty, in the 18th year of Augustus Caesar, this obelisk was moved to Alexandria, The Royal city of Cleopatra.
From Alexandria, it was brought to England in 1878 as a token of celebration for the victory over Napoleon in 1815. I just can't see the connection as to what an Egyptian obelisk has to do over an English victory! It was sad to learn that even in those days tax payers' money was spent on bringing this kind of treasures from afar.
It is believed that the two sphinxes facing each other guard the obelisk.
Luckily, I was in good company when I was roaming here. From what I understand, the obelisk at the Embankment, London has a twin in New York. Wish to visit the twin as well:)