Ask HN: Visiting Bulgaria and Romania: Where to Stay? What to Do? Who to See?

Looking for advice on getting the most out of the city from a startup perspective. I'd love to have the potential to meet a few freelancers or dev shops in the area face to face.

I wouldn't mind having some advice as far as where to stay, anything I have to see or do while I'm in the area. As a first time visitor, is their anything I just cannot miss?

I wouldn't mind building a good network of contacts that have a potential for friendships or working relationships.

To put it bluntly, what would you share with an American coming to Bucharest, Romania. Then Burgas and Sofia in Bulgaria.