RE:fly fishing in Bonsia
I'm still not convinced this isn't a troll, but I grew up in nearby Croatia and can offer some hints. Remember, southern Europe is the home of Salmo Trutta, aka brown trout, and you will still find wilod browns prevalent, but very cagey. I'vre seen fish up to 8 kg come out of totally improbably streams. There's also been a lot of arctic grayling and rainbow trout introduced, mostly to reduce pressure on native browns. the headwaters of the Bosna river, right near Sarajevo, are a well-known brown trout fishery. It was, sadly dynamited during the war, but I believe fish have been restored. Similarly, the upper Neretva river has a good population of wild browns. Look for rivers originating high in the limestone mountains. In upper Bosnia, the Sava river and its tributaries is a decent pike, carp and wallweye fishery, but it's tough fishing.
These waters have not been fished heavilyt with sophisticated fly tackle, andf the fish are relatively uneducated. The locals mostly go for them with mepps spinners, earthworms and 12'-16' cane rods, 'dappling' flies. Yoou will do very well with a run of the mill collection of dries and nymphs. Same stuff we'd use here.
One word of warning: the laws in the country are somewhat arbitrary with fines and hassles sometimes out of total proportion to the offence. Make sure you find a local sportfishing club and work with them. They will most likley want to stick you with outrageous 'fishing licences' and such, but if you persevere and are polite, they'll become reasonable quickly. There is no organized guiding as we know it, so don't go around offering big bucks for fishing. Yo'll be taken for a mark or suspected of omething worse. A box of flies and an offer to show how they're used will go much further than cash.
Think of this as a high-odds chance to hook up with a 15+lb truly native brown.
Email directly if yo'd like more details