In one sentence: Best tour I ever had so far, compared to a few other city tours I attended in Stockholm, Sydney, Istanbul and Budapest. Plamena guided us through many bigger and smaller sites of interest. I was bombarding her with questions every two stations and she could answer all of them in perfect English, which you wouldn’t expect from a non-native speaker. We were 6-9 people in our group and went from the central post office through the main walking streets, the old town, passing by some museums all the way up to one of the big hills with an astonishing view over the city. The tour is actually not for free, since there is a donation very well appreciated to support the project and the guide. So bring some notes, maybe not your 50 Leva one, which you just got from the ATM, maybe not your last 2 Leva note, but anything in between shall do fine. The tour lasted two hours and I would recommend it to anyone who wants to get a first impression about the city before exploring it on ones own.