Hey @danielapetk those Bulgarian mountains sure look nice. Adventure-sky-running looks cool also although I'm not sure my knees would agree these days. I found, on the Kokoda Trail, that coming down was the hardest thing. It was very slippery and with all the root-networks from the trees...A challenge. I posted about it months and months ago and have dug up the links for you if you're interested.
There's a history behind the trek and my posts tell a little about it as well as my own journey.