Gorgo (1961)

Synopsis
Gorgo is an attempt to make a Japanese-style "giant reptile" flick in an English setting. The story begins when underwater volcanic activity in the Irish Sea brings forth a 65-foot monster called Gorgo. Enterprising Joe (Bill Travers) and Sam (William Sylvester) capture the beast and transport it to London, where Gorgo is put on display as a seaside carnival attraction. This proves to be a major mistake when Gorgo's even larger mother lumbers to the surface in search of her cute li'l baby. In short order, London is trampled and trashed. ~ Hal Erickson, All Movie Guide