And they might have still had Oral Legends
Of the Black Sea infill that occurred not long after the end of the last Glaciation period. The entire region is rife with evidence of numerous examples of natural catastrophes, violent Vulcanism, Severe Tectonic events, Climate shifts, ad infinitum.
Sorting out truth from legend is difficult at this distance.
Makes one wonder how Humans built anything that lasted.
Links;
http://www.nationalgeographic.com/blacksea/ax/frame.html
http://www.answersingenesis.org/docs/4168.asp