Thank you! :) Never been in Sofia. But Veliko Tarnovo was amazing.
You should visit Georgia - not far from Bulgaria. Batumi, Tbilisi, and Svaneti region (a high mountain valley) are must-visits. If you don't mind having Turkey as a transit country, it's cheap to visit Georgia too - there are buses from Bulgaria to Istanbul and from Istanbul to Batumi / Tbilisi (for example metroturizm.com.tr). I traveled in this way myself :)
Oh, thanks for the pointers and recommendations! You made a wonderful choice with Tarnovo. To some extent, you don't even have to go to the capital. It is not as beautiful as a smaller town can be.
Maybe you were lucky with your trip then, because acquaintances complained about the great chaos and disorder they encountered this year trying to get from Bulgaria to Turkey by bus. But I will keep this route in mind. Thank you! 😊