I am the official currency of a nation that straddles two continents, boasts a rich history as a crossroads of civilizations, and is famous for its unique geological formations like the 'fairy chimneys'. What am I?

1. My banknotes often feature prominent historical figures.
2. I am used in a country that is a popular tourist destination due to its historical sites.
3. My value has been subject to significant fluctuations in recent years.
4. The country using me has a unique culture blending European and Asian influences.