Some days I get reminded how little ancient or even modern Greek I know. I'm not the best with languages, and although I'd love to say I have a special Percy Jackson-esque ability to read ancient Greek without effort, I don't. My understanding of the ancient language is one I hope to increase in the coming years, and when I do, perhaps I could travel to Turkey for some practice.

This video, by the University of Cambridge, shows a bit of the journey of  Cambridge researcher Dr. Ioanna Sitaridou, as she travels to north-eastern Turkey, where an endangered Greek dialect which closely resembles ancient Hellenic is still spoken. The dialect, called Romeyka, is far more widespread than the tiny mountain villages of north-eastern Turkey, but because of the remote location of the towns, their version of the dialect was influenced far less by contact with other languages and dialects that the more widespread version of Romeyka. The discovery is labeled a linguistic treasure trove by researchers.

Because this is not my area of expertise at all, I'm going to copy/paste wiki for a bit of history on the Romeyka language:

"Pontic Greek (Greek: Ποντιακή διάλεκτος or Ποντιακά), is a form of the Greek language originally spoken in the Pontus area on the southern shores of the Black Sea, northeastern Anatolia, Eastern Turkish/Caucasus province of Kars, southern Georgia, and today mainly in northern Greece. Its speakers are referred to as Pontic Greeks or Pontian Greeks.
The linguistic lineage of Pontic Greek stems from Ionic Greek via Koine and Byzantine Greek and contains influences from Georgian, Russian, Turkish and to a lesser extent, Persian (via Ottoman Turkish) and various Caucasian languages. Pontic is most closely related to Cappadocian Greek, and the Greek spoken in Mariupolis (and formerly in Crimea, Ukraine) (see Mariupolitan Greek).
Historically the speakers of Pontic Greek called it Romeyka (Romeika, Greek: Ρωμαίικα), which, in a more general sense, is also a historical and colloquial term for the modern Greek language as a whole. The term "Pontic" originated in scholarly usage, but has been adopted as a mark of identity by Pontic Greeks living in Greece.
The inhabitants of the Of valley who had converted to Islam in the 17th century remained in Turkey and have partly retained the Pontic language until today. Their dialect, which forms part of the Trapezountiac subgroup, is called "Ophitic" by linguists, but speakers generally call it Romeyka. As few as 5,000 people speak this dialect. Estimations show however that the real number of the speakers must be considerably higher.
Ophitic has retained the infinitive, which is present in Ancient Greek but has been lost in other variants of Modern Greek; it has therefore been characterized as "archaic" (even in relation to other Pontic dialects) and as the living language that is closest to Ancient Greek. A very similar dialect is spoken by descendants of Christians from the Of valley now living in Greece in the village of Nea Trapezounta, Pieria, Central Macedonia), with about 400 speakers."

It's striking to me how different the pronunciation is between these speakers and, for example, the young man below, who is trained in ancient Greek (and Latin, Italian, Russian, Japanese, etc.).

I am sure dialect is part of the difference, but I think the biggest difference comes from years upon years of use. For the young man above, ancient Greek is a subject of study. For the men and women in the Turkish mountain villages, their language is their language; they were raised with it. Their version is a lot less 'clean'. I value this young man's recording, I love hearing the women in the other video speak. It sounds far more like the way the ancient Hellenes would have spoken with each other, although that opinion is, of course, subjective.