The King James translation of the Bible speaks of there being "giants in the land" in that pre-flood world. Genesis 6:4:

There were giants [nephilim] in the earth in those days; and also after that, when the sons of God came in unto the daughters of men and they bare children to them, the same became mighty men which were of old, men of renown.

Then, about a thousand years after the Genesis Flood, when the Israelites had sent spies into the promised land, they reported in Numbers 13:33:

And there we saw the giants [nephilim], the sons of Anak, which come of the giants: and we were in our own sight as grasshoppers, and so we were in their sight.

The Hebrew Lexicon gives nephilim the definition as "fallen ones."

Medieval churches often had fossil bones on display, purporting to be part of some ancient giant and, in this way, sustaining belief among their congregation. In the late 1700s in England, a living giant appeared known as "The Irish Giant," while in 1869 in Cardiff, New York, a fossil giant was dug up and given the name "The Cardiff Giant." Both were used and are still sometimes used by believers to support Scripture.

Here Are the Facts:

Charles Byrne was born in Littlebridge, Ireland, in 1761, and by the time he was twenty had grown so tall that he came to the attention of a showman, Joe Vance. Vance took him to Edinburgh, where Charles was able to light his pipe on the then-new street lamps. Promotional advertising often claimed the "Irish giant" was thirteen feet tall. At this time, two other claimants to the title "giant" were made by men who also happened to be from Ireland, so that there were now three "Irish Giants"! Charles Byrne fell into bad company, drank very heavily, and finally died in his twenty-second year (1783). Fortunately for our account, his body was quickly acquired by surgeon John Hunter, and Byrne's skeleton is one of the prized possessions of the Royal College of Surgeons of England.

In 1909, Dr. Harvey Cushing was able to determine the correct etiology of Byrne's abnormal growth, but, vital for our story, we have an exact measure of the Irish Giant's actual height. It is seven feet, seven inches, meaning he was no more than seven feet, ten inches in life. 

And the Cardiff Giant? It was a 10½ foot piece of carved stone – a pure fake!

Bonderson, Jan. 1997. A Cabinet of Medical Curiosities. NY.: Cornell University Press. Pages 90, 193.