Brasov
This is Transylvania ground-zero and arguably the best base of operations for regional tours. The city itself is a Saxon town of the first order, complete with medieval walls, crumbling cobble stone streets baroque facades and churches, including the whopper Black Church. Walking around town is a pleasure. The downside is that it suffers from the usual tourism saturation problems, namely ambitious prices and the odd pickpocket. Still, compared to similarly important cities in Western Europe, Brasov is safe as a monastery and an undeniable bargain.
The surrounding hills provide lovely ambiance, if you can overlook the giant ‘Brasov’ sign mounted and lit at night, Hollywood-like. If you can duck the tourist gruel, there are several decent restaurants here, including my personal favorite Bella Musica across the street and several steps down from the Black Church at Str George Baritu 2.
There are numerous day-trips to castles and mountain hikes being hawked by virtually everyone in town. Prices for these day-trips are nearly identical, but it wouldn’t hurt to shop around a bit before settling on a trip. Tours include package trips to the castles at Râznov and Bran and wine tours in Prahova Valley.
Simply Brasov has loads of detailed local information. You can rent bikes and arrange city walking tours at Active Travel.