Bacho Kiro is a beautiful cave located close to the town of Dryanovo as well as around 20 km away from Veliko Tarnovo - the old capital of Bulgaria!
You can visit the cave by car - just head to Dryanovo monastery (Google maps will take you there, it is very close to the main road between Gabrovo and Veliko Tarnovo), leave your car at the parking lot in front of the monastery (they will charge you a small fee like around 1 lv per hour) and walk for about 10 minutes to reach the cave (there are signs which will take you to the cave). It is quite confusing if you set "Bacho Kiro cave" on Google maps, as the road actually ends at Dryanovo monastery. This is why it is better to set the GPS to take you to the monastery and then head to the cave by foot. At the bridge in front of the monastery you can go right (on a small alley) or after visiting the monastery, you should cross the wooden bridge behind it and again end up on the same alley which leads to Bacho Kiro cave.
Another option is to travel by train and to get off at Bacho Kiro railway station. The train usually runs between Gorna Oryahovitsa, passes Veliko Tarnovo and its final stop is Stara Zagora (or of course, the opposite direction). So travelling by train is convenient if you live in Veliko Tarnovo or Stara Zagora and it is also the best option if you want to enjoy the scenic train trip when crossing the Balkan mountains.
The way from the parking lot at Dryanovo monastery to the cave is indeed short, but quite nice - on the right side you will see the Bacho Kiro chalet and right next to the stairs leading to the cave you will also see a small waterfall. You can also spend the night at Bacho Kiro chalet or Dryanovo monastery.
The cave is open all year round, but make sure you check the opening hours in advance. Usually, the cave is open from 9 AM to 6 PM (1 April to 30 October) and from 10 AM to 4 PM (1 November to 30 March). The entry fee varies (for instance, you get a discount if you are a student), but in general the fee for an adult is around 3 BGN. It takes around 15-20 minutes to see all three levels of the cave. The staff also offers a tour for around an hour with a tour guide. The fee in this case should be around 6 BGN, but there should be a group of min. 15 people. You might be able to join the tour at 2 PM in the summer months when it is not necessary to have minimum 14 more people in order to start the tour. Keep in mind that it is cold and slippery in the cave!
Inside the cave you there are colorful lamps which light up the cave. An interesting fact is that signs of human workmanship which date back to 50 000 BC have been found in the cave, so visiting the cave with a tour guide who will tell you more about it is definitely a good option! At the end of the cave you will also visit a big hall where wedding ceremonies take place.
On the right side of the entrance of the cave you will see a couple of signs - one of them marks the start of the 5-hour ecotrail to the beautiful architectural reserve Bozhentsi. The second one shows you the path to the Love Bench viewpoint and another one leads to the ruins of an old fortress. All three routes share the same "start" (stairs, actually), but soon the paths split.
Close to the wooden bridge behind the monastery, you can also go for a walk to Sini vir waterfall (it takes around 15 minutes), so there is definitely quite a lot of things to see in the area! Visiting the town of Dryanovo (around 6 km away from the monastery but also accessible via train or car) is also an option - the museum of the famous Bulgarian architect Kolyo Ficheto is located there.