Absorb London's many wonders from two different perspectives: atop the UK's highest observation deck and by boat tour along the Thames. The Shard, glittering masterpiece of architect Renzo Piano, reaches 800 feet into the sky and offers a panoramic view that stretches 40 miles. Witnessing London laid out like patchwork into the horizon is a rite of passage every visitor should undertake. For a fresh angle, step aboard a Thames City Cruiser for a tour down the expansive river, aided by the guide's encyclopaedic commentary. It offers front row seats to all the riverside icons, like the Coca-Cola London Eye and Tower Bridge. Take advantage of a full day pass that allows guests to hop on and off as the mood strikes. Don't forget to bring a camera