Lakatnik is about one hour outside of Sofia and there is a train stop which is perfect to start your trekking from. You will cross a bridge over the Iskar river and then walk up through a beautiful forest with an incredible panoramic view. After about one hour you reach one of the many caves you can find here. These natural caves date back to around 130,000 BP and have different difficult levels that suit both beginners and experienced cavers. If you don’t like cave’s (or bats) you can just enjoy the fascinating view! This mountain also has some perfect walls for climbing if you know what you are doing.
Skakavista is two hours from Sofia and is most easy to reach by car. If you don’t have a car available you can also take two buses to get there. Skakavista is perfect for a weekend trip as there is a big hut up in the mountain (within 1-2 hours walk) where you can stay if the weather is not suited for tenting. This place is most famous because of it’s beautiful waterfall and on the other side of the mountain it’s lakes. In the winter the waterfall is turned into ice and great for ice climbing. If you are here in the summer you can instead take a dip in the small river that goes down the mountain.
Both these places are great both for beginners and advanced trekkers because you can find varied level of difficult tracks.