At Dobrinishte, the last outpost of civilisation, we used the bathroom of a nearby club, then stocked up on biscuits and crisps, as the chalet that would be home for the next six days lay six km away in the wilderness, accessible only by cable lift.

A former German army bus took us to the bottom terminal, on the north-east face of Pirin Mountain. Once on our way up, two overriding sentiments collided within me: one of awe of the broad mountain range and valleys all around, carpeted green with the Macedonian pine, silver fir and beech trees of July. The other of acrophobia as our light-framed seats dangled from a single rod some 10-25 metres above the slope.

The question of who had built this system, either the Soviets, or more recently by Swiss, dogged my mind; whenever my seat would wobble high above rocky terrain, I prayed it was the latter.

At the opposite end, we check into the Bezbog Chalet, and hauled our backpacks up five flights of stairs to the attic room, where 16 musty beds, perfumed somewhat by clean, new linen, awaited us.

Fifty metres away lay Bezbog Lake, the first un-trashed, un-murky body of water I had encountered in Bulgaria. The occasionally darting of mini frogs or splashes by a mountain trout on the otherwise still water provided the only signs of life in it.

To its west towered Bezbog Peak. At 2645 metres, its name in Bulgarian means "without God". As the story goes, some villagers fleeing advancing enemy forces took refuge at the top. There they prayed for deliverance… to no avail. The tragedy was put to good use during the communists' renaming scheme, though it squares oddly with the name of its parent mountain range, derived from Perun, the ancient Slavic god of thunder.

At the peak's base stood what appeared to be a Cold War relic: a concrete bunker not unlike those that dot the Albanian countryside.

"That's the remnant of the original chalet that had been destroyed by an avalanche," explained Toni, a teacher who had organised the trip. "Likewise its reconstructed successor, and hence its present location further down."

That evening we had our first supper in the chalet dining room, its remoteness not the least diminishing the homeliness of the fare on offer, including soups, salads, casseroles, stews, grilled meats, pastries. My spirits would have been higher were it not for a pounding headache I had incurred on the way up.

The following morning though, I woke up to discover that it had completely abated. Descending the stairs, I surveyed the extent of our company: hordes of trekkers frantically being served breakfast, factory-style. Replete with rucksacks, alpine clothing and gear, they soon set off in groups of 15, fanning out among the various trails. Unlike Zlatni Pyasutsi (Golden Sands), almost all those present were speaking Bulgarian and were non-young. By 7.45am, the hotel was deserted, except for our party of sleepy-heads.

An hour later we too were marching, south to Tevno Ezero (Lake) along the lower slopes of purple-greyish mountain peaks and ridges.

Bobby, a seasoned hiker, set a brisk pace, while the rest, nine teenagers and four "old people", struggled to keep up in a single file amidst dwarf juniper shrubs. Colour-coded bands, resembling flags, painted on rocks and cairns marked the trails, broken every so often by alpine streams, crystal clear and icy cold.

After walking three km we reached Popovo Ezero, or Priest Lake, so called because as legend has it, a priest, fleeing his pursuers, jumped in - and vanished, with only his hat remaining afloat. This magically turned into an island near one end.

Despite its very inviting nature, and an air temperature of 22 °C, no one was about to follow suit. Evidently all the Muscovites were splashing at Slunchev Bryag (Sunny Beach).

From this point we began hiking upwards, literary gaining an overview of a procession of small lakes, bright blue, nestled in valley gorges and feeding into one another.

And whenever we scaled what we though was the king peak and had a brief rest, Bobby would extol us: "Let's scale that one over there…" The trail grew steeper the higher we went, with solid ground giving way to rocky terrain, making progress awkward.

After reaching a saddle that afforded a wide view of Mount Vihren (2914m), the highest peak in the Pirin some 10km distant, Bobby had an announcement to make. "We took a wrong turn somewhere." Finishing lunch, despite our onward momentum, he headed us back.

Going downhill proved more fun, but no less tricky. Dark clouds soon began to gather, followed by rain, lightning and thunder, its decibels amplified by the valley walls, living up to the region's namesake. Slogging though puddles, we behaved like perfect conductors, but made it back positively charged. "We depart at 7.30am tomorrow," said Toni.

The following morning, however, she said that weather reports had indicated rain, so it would be less dangerous to stay in. Unfortunately the sky remained bright and clear all day.

On Thursday, we tackled Bezbog Peak in our mists. Compared to the irregular trudging on Tuesday, this proved straightforward, our only obstacle being stunted pine scrubs. From the top we could see the valley and towns to the north-east, and ever more jagged peaks and ridges to the southwest. Onward ho!

The trail soon converged into a winding, narrow path, to the point where many places felt like a blunt knife's edge.

This proved hardly a put off, for we found Polezhan Peak (2851m) pimpled with cairns, reminiscent of Egyptian worker tombs. At this point Bobby ordered the under-aged hikers to return with Lucy, an adult.

As the remaining three carefully negotiated our way on the Strazhete Ridge, two figures descended towards us with the spring of mountain goats. They turned out to be men in their 70s, who admonished us to skirt the upcoming peak. And for good reason.

It was practically vertical, and at one point the path gave way to a precipice some 40m from a saddle top. Passing over, we had to hug the cliff side, Bobby specifically instructing us to grip a particular rock outcrop to keep our balance.

Emerging whole, the surroundings continued to grow depth and grandeur; yet we encountered no one else. "You should visit Rila; you won't feel lonely," advised Kristina, another mountaineer.

Vegetation here consisted of alpine meadows, fitting for a cheese commercial, while the upper peaks were largely bare save sporadic clumps of edelweiss. And with the exception of a scurrying mouse, no animals displayed themselves.

Upon conquering Disilitsa Peak (2700m), Bobby phoned back and waved his jacket (Toni later said she could just barely make us out, 2.5km away).

Returning would be an easy, downhill prospect - or so we thought. The valley floor proved more difficult due in various places to large boulders, streams and thick vegetation.

The following day, we once again set off for Tevno Ezero, knowing well where not to tread. Along the way we encountered a string of small lakes leading to Valavishki Ezero, which topped Poporo Ezero with its two distinct islets. With each passing lake, I found myself feeling increasingly demystified.

By noon we hit Tevno with its guest lodge, and along the shore its lifeline: two grazing horses, and a mule. Even out here, they served good Bulgarian cuisine, even fish. Or, as one of the hikers pointed out, "hunger is the best recipe". Later another team arrived, displaying no signs of wear or fatigue. "We started early and took the easy route," explained Suzana, who looked more at home in a library than out here. Easy route? Where?

Refuelled, we resumed our circuit, the biggest spectacle occurring as we descended a saddle. Confronted by a 60m sheet of ice, Kristina sitting at the top suddenly began sliding down as if on an kiddy park slide. We held our breaths as she sped towards the end, demarcated by big rocks. Luckily she came to a gentle stop. "Do that again so we can film it," requested someone.

Back at base camp, to cap off our stay, the students put on a performance. It featured a bear (Stoicho) who stumbled upon a joint.

Becoming habitually stoned, he falls into the bondage of a wily woman (another boy in a florid dress). With other characters tossed in including hustlers and hussies, it devolved into a chalga musical. By this time a woman in the audience walked out, tugging her little son along.

As it happened, Nadezhda and Valentina's birthdays also fell on that day, so they each received presents of recycled soda jugs containing sphagnum moss, muddy water and frogs (later released).

Bezbog Chalet ("hizha" in Bulgarian)
Elevation: 2236m
Tel: 048/ 906 209, 088/ 828 61 02, 07447/ 2120, 2129
Sleeping places: 130

Tevno Ezero Lodge ("zaslon" in Bulgarian)
Elevation: 2512
Tel: 07443/ 2683
Seating places: 30