A tsunami in Ireland or the U.K. is pretty much unheard of but according to experts, one such incident caused the deaths of over 2,000 people in England back in the 17th century.
Tonight's BBC Four documentary
The Killer Wave Of 1607: Timewatch will tell the fascinating story of how high floods in the Bristol Channel decimated areas such as Devon, Somerset, South Wales and even Glastonbury which lies 23km from the coast.
Over 2,000 people are thought to have drowned in the disaster, livestock was destroyed and numerous houses and villages were swept away. In 2002, a research paper was issued following investigations by experts Simon Haslett and Ted Bryant which suggested that the flooding may have been caused by a tsunami. The theory is based on eyewitness accounts in the historical reports which described the flood.
In tonight's programme, the pair present their hypothesis of the 12m-high wall of water that hit in 1607 and is still thought of as Britain's worst natural disaster, largely forgotten with time.
Even though the documentary was first broadcast in 2005, it's well worth a watch and you can catch it on BBC Four tonight at 11.10pm.
