>>2589629I can only tell you about Croatia, which is kinda the tamest in terms of terrain and infrastructure, so not that useful.
The season and the weather decide where going out is best. Before May high alpine terrain in the Balkans is under snow and weather can be severe. In Croatia that would be a good time to hike the islands and lower hills.
May and early June are good for most hiking, but it's already too hot on the islands and on the coast in parts without shade (unless it's a windy day, like last weekend).
In the summer its simply too hot to hike anywhere except the higher regions. The mountain terrain comes alive in summer and is truly beautiful, but water is an issue.
Long distance hikers mostly do Balkans in the spring.
The best hiking in Croatia is the Velebit mountain range, starting in North Velebit NP and ending in Paklenica NP. Biokovo is cool. The islands are cool if it's cold, there are also bridges to Krk and Pag. Dalmatia and Lika have the most dramatic terrain.
Mine areas are a thing in Bosnia and in parts of Croatia mostly near Bosnia. It's unlikely that you'll be close to them but if you're going off trail you need to check.
Montenegro is supposedly great. Incredible mountains and canyons, sea, tourist infrastructure.
Albania and Kosovo are mountain paradises but just about the sketchiest places in Europe.
Greece should also be great, especially the coast is underrated.
