From what I remember in history class, Lithuania was the last European country to adopt Christianity and abandon paganism in the 1400s, but did any notable pockets/portions of populations maintain a pagan faith well into the modern era?

It always seemed interesting to me that religions such as the Ancient Greek and Roman religions, which retain so much beauty and contributed so much to society, would be able to sort of “vanish” over time.

Lastly, I’m aware that in modern times there has been a resurgence of ancient European polytheism but would prefer to focus on continuous groups.