I recall some of the Orthodox denominations still do mass in Latin. I visited an Antiochian Orthodox Church for a class where this was the case. I think (it has been a long while) the key phrase you'd look for is 'Western Rite'.

Some Eastern Orthodox use (for all dialogue, they do celebrate mass) a language that's now only referred to as Church Slavonic. [1] Though going down this tangent I can't help but think of that Emo Phillips skit on religion: https://www.youtube.com/watch?v=ANNX_XiuA78

[1] - https://en.wikipedia.org/wiki/Church_Slavonic

Latin (and other "old" languages) can still be found in various ways and places, though that starts to get deep into it, as the "New Catholic Mass" can be said in any language, one of which is Latin.