River Thames frost fairs River Thames frost fairs River Thames frost fairs were held on the tideway of the River Thames at London in some of the winters between the 17th century and early 19th century, during the period known as the Little Ice Age, when the river froze over. During that time the British winter was more severe than it is now, and the river was wider and slower, further impeded by the medieval Old London Bridge. Even at its peak, in the mid-17th century, the Thames freezing at London was less frequent than modern legend sometimes suggests, never exceeding about one year
Tunnels underneath the River Thames the Port of London, which until the 1980s required large ships to be able to access the river as far upstream as the City of London. Until the construction of the Queen Elizabeth II Bridge in 1991, the easternmost bridge on the Thames was Tower Bridge in central London. Even now, the Dartford Crossing provides the only way to cross the Thames by road between London and the sea (with predictable results for traffic congestion). The width of the river downstream meant that tunnels were the only options for crossings before improvements in technology allowed the construction of high bridges