Only in London: new campaign launched by Visit London

These are some of the highlights recommended by Only in London - VisitLondon.com: Stand Where Time Begins on the Greenwich Meridian Line See the World's Largest Cut and Polished Diamond at the Tower of London Enjoy the Sights of London from on Board the London Eye Visit Tate Modern, the Most Popular Art Gallery in the World Wander around Portobello, the World's Largest Weekly Antiques Market Marvel at Shakespeare's First Folio, the Magna Carta and Handel's Messiah at the British Library Speak at the same place as George Orwell on "Speakers Corner" in Hyde Park Stroll through the home of the world's largest living plant collection of 30,000 different species of plants, the Royal Botanic Gardens, Kew Get your sea legs on HMS Belfast – Europe's largest surviving armoured warship Take in a Shakespearean play at Shakespeare's Globe, in the area where he lived and worked Travel on the world's oldest subterranean travel system in the world – the London Underground Hear the chimes of the world-famous Big Ben at the Houses of Parliament, the world's largest four-faced chiming clock Pay your respects to a host of literary greats in one place – from Dickens to Chaucer to Kipling to Tennyson – at Poets Corner, Westminster Abbey See British law-making in action at the Houses of Parliament during the summer opening