AdExplore London From The Thames. Free Cancellation & Full Refund Up To 24 Hours Before. Full Refund if You Cancel at least 24 Hours in Advance. Book Now. Do More with Viator.
The River Thames, known alternatively in parts as the River Isis, is a river that flows through southern England including London. At 215 miles, it is the longest river entirely in England and the second-longest in the United Kingdom, after the River Severn.
Etymology: Proto-Celtic *tamēssa, possibly meaning "dark"