I visited a bunch of countries. I also can add Romania and Moldova to the list, but I just spent 4 hours there, so I don't consider these places as the ones I've visited. I also can't say I've seen the entire Russia, not gonna lie this country has lots of wonders and fascinating things to observe, but I just don't have enough interest in discovering my own homeland. However, if we speak about precise locations I would say the following:

Sverdlovsk Region, Chelyabinsk Region, Vologodskaya region, Moscow, St. Petersburg, Sochi, Krasnodarskiy Krai

Kiev, Crimea (before 2014, so idk what's going on there now haha)

Minsk

Gdansk, Malbork, Frombork

Nesebar, Burgas, Chernomorets

Alanya, Antalya, Marmaris