My daughter (class of '28) will be attending an archaeology field school in Sozopol, Bulgaria for the month of June. Because flights over there don't line up well timewise with the start of the school, I'm going to fly out with her a few days early to Sofia and we'll have some time to explore the city before she heads to the coast for the school. Has anyone been there before? Any suggestions for hotel location within the city, restaurants, sites to see, etc?