In fact there are three obelisks bearing the popular misnomer of "Cleopatra's Needle"; one each in London, Paris in the Place de la Concorde., and New York City erected in Central Park, just west of the Metropolitan Museum of Art. All three needles are indeed genuine Ancient Egyptian obelisks but were already over a thousand years old in the famous Queen's lifetime.
1. Originally called tekhenu by their ancient Egyptian builders, an obelisk is a tall, four-sided, narrow tapering monument which ends in a pyramid-like shape or pyramidion at the top. Ancient obelisks are monolithic, i.e. they consist of a single stone. The ancient Greeks who saw them used the Greek term obeliskos (ὀβελίσκος) to describe them (from obelos (ὀβελός) meaning "spit, nail, pointed pillar").