Black winter birches cover the steep slope, their naked skeletons creating a colonnade which hides the foot of the hill, so the creek running there is only heard, not seen. White mist rises from the ravine, red leaves cover the ground. All around are more trees, more hills, more mist: this secluded landscape in the Rhodope, beyond the now disused barbed-wire fence which, under Communism, sealed off the border with Greece, stretches to the horizon.
Comfortably spread out on a narrow plateau overlooking the dramatic landscape of Veliko Tarnovo, the traditional village of Arbanasi is something of a conundrum. It is an architectural heritage site, yet it is filled with mansions and hotels in dubious "traditional" style, all built in the past 15 years.
The busy Władysław Warneńczyk Boulevard is the road you need to take through Varna to reach the Sofia-bound motorway. It is also the road to one of Bulgaria's strangest and most moving museums.
Among the firs of the park – an oasis of calm amidst the urban buzz – two Thracian burial mounds stand. One of them, adorned with a monument, encloses a burial chamber where lies the stone effigy of a medieval knight.
A medieval knight? In Bulgaria?
"To the Small Basilica, please," we say to the taxi driver we hail in the centre of a warm, autumnal Plovdiv. Then we realise. The driver is very unlikely to know the whereabouts of Bulgaria's latest archaeological museum, only one day after the official opening.
The massive stone crosses that centuries ago used to be the graveyard of Garlo village, in the region of Pernik, poke out from the undergrowth, a poignant sight that we have covered several times in Vagabond.
This time we are in this picturesque, atmospheric and overlooked part of Bulgaria for another reason: to search for one of this country's most enigmatic archaeological finds.
When you see Karlukovo, near Lukovit, for the first time, you'd be hard put to believe that you are in the part of Bulgaria richest in karst rocks. The settlement lies among low, monotonous hills and there's nothing – not even a signpost pointing to a tourist sight to indicate that underneath this modest landscape lies a labyrinth of caves. It is the result of thousands of years of action by wind and water, which carved the pliable karst rock and formed caves, magical shapes and whirlpools.