After something a bit different this winter? Sick of the British weather? Paul Bonson and John Walker recount a snowy traverse of Musala (2925m), Bulgaria's highest mountain, via its North and North West Ridges.

One minute I'm walking round a well know outdoor shop when a book catches my eye; six months later - in April 2013 - I'm stood outside the Yastrebets ski lift station in Borvets, waiting for the first Gondola to take me and my pal John halfway up the highest of Bulgaria's Rila Mountains.

The book is the Cicerone guide to Europe's High Points and for a fairly inexperienced climber like myself it seemed to be an ideal tick list.

We had tried to get information on the routes on Musala, the highest point in Bulgaria, as the book only cites the 'tourist' route, and even under snow that seemed a little tame. Also the topography screamed for a circular traverse. We got a map from Stanfords, but at 50k scale and with 50m contour intervals, it didn't give too much away. We posted on UKC and elsewhere for information, but the best we got was a couple of folk who had done the traverse in summer and one person from UKC who said it looked 'tasty'. That whetted our appetite, and looking at the small pictures on Summitpost, we judged it to be around II/III Scottish, maybe PD+/AD-, but we were sure it would have ways around the difficulties if it was so easy in summer. Oh, a mountaineers optimism.

We'd flown into Sofia the previous day, driven about an hour south to Borovets, checked into our apartment which was really cheap out of season and then stocked up with food a drink for the following day on the mountain. After an evening researching the route in Borovets, ('Yeah, up here along there, do you know it? No? Oh well, another couple of Kamenitzas then') we find ourselves at the Yastrebets uplift for the first car of the day. By 9.20am we're at the top ski station summit at 2396m.

It was already clear that the mountains were going to be deep in snow and with fresh powder in parts. Fortunately an overnight frost made the downward traverse bearable although crossing the iced pistes required crampons. An hour later we arrived at the large Musala refuge, (normally used by pilgrims, as Musala is quite a holy mountain in Bulgaria apparently), closed at this time of year and deep in snow. We had a decision to make, up and down the standard route on the west side of the hill, or try to ascend via the longer North and North East ridge. As the winds were very light and the powder not too deep we headed for the classic 'summer' ridge route.

"The climbing quickly became more difficult, the ridge very narrow and banked with fresh powder, with cornices on both sides"

Our first target was the obvious col just below the Ireeek summit, where there is an interesting rock formation called the Sfinksa (Sphinx), and it certainly does look like its Egyptian counterpart. Well it would have been an obvious col had the cloud not descended halfway up the climb.

We kept to the right of large crags and found our way around a small cornice and onto the ridge. From here an upward ridge walk and a few short scrambles brought us to the minor summit, navigation was becoming tricky with the larger scale map as the section before (a section only printed in Cyrillic, Noeyek, at 2852m) flattened. Finding the ridge again, we roped up and climbed for an hour to the top of Malka Musala (Little Musala). We'd chosen a 30m rope and a half rack, which for this section is more than enough as very little protection is required, and we weren't expecting major difficulties further on.

Still in the cloud at the summit of Malka Musala a judicious compass reading was taken to be certain of our downward SSW direction. We were aware that the next ridge section was likely to be more difficult from the photographs we'd seen, but what we had underestimated was the combination of route length and technical climbing in winter conditions. It became clear to us now at about 2pm that summiting and returning to catch the last lift to Borovets at 4.15pm just wasn't an option. Fortunately we'd read that the weather station at the summit is open all year round and offers refuge so that took the pressure off, and allowed us to just concentrate on climbing safely in the fresh powder.

The climbing quickly became more difficult, the ridge very narrow and banked with fresh powder, with variable cornices on both sides. My more experienced climbing partner estimated this long ridge as Scottish Grade II/III. In between the sections where we could rope and move together we needed to make about 20 pitches and a 60m rope would certainly have been better. Still for me as a relative novice the short rope communication definitely helped. We chose to stick to the crest wherever possible as the powder snow to the side was deep and on steep ground. We'd already heard a number of distant avalanches rumbling like thunder across the mountains, and these focused the mind!

A couple of the pinnacles needed to by bypassed, as the chimneys were filled with snow and assured footwork was required on extremely steep ground. It was four hours of full on up and down climbing along the ridge now, the really interesting part being the uncertainty of a route off.

Approaching the latter section the weather improved significantly. On the one hand we were now getting great views of the mountains; on the other the final upward ridge loomed above us with what looked to be impossibly narrow sections. Another hour of climbing and we came to what was hopefully the last obstacle. It was now about 7.30pm and we were being treated to late evening sunshine whilst looking at a long corniced ridge that was going to be difficult to protect. Nothing for it... I stood aside to let my more experienced climbing partner lead! Once crossed, it was clear we were going to be able to walk off roped together and I was having a major breakout of elation.

We finally arrived at the summit at 8.15pm just as the sun was setting. Now all we had to do was find a way into the hut. A full 360-degree inspection revealed most of it to be inaccessible due to snow, however there was a small tunnel leading to a likely looking window, and after banging on it for a while, a firm shove with the back of a walking axe saw it swing open. Once inside things improved rapidly, and Rosen the onsite resident weatherman turned up and offered us tea and brandy. There was a really toasty bunk room and a drying area in the kitchen. The meteorologists do one week on and one week off, and double up as de facto hut guardians when not taking their readings.

An hour later, after warnings from Rosen that 'I have not seen any British in 15 years here, and any Germans that come here will never eat our soup' we were tucking into the local delicacy, tripe soup (I've learnt now that it's best not to ask and just eat) and sharing whisky. You have to have a slug of the local whisky (Rakia) before eating the soup... funny that! My friend gave him some our Glenlivet, much to his delight. After an hour or so exhaustion took over and we collapsed on our mattresses. It's strange how difficult sleeping is at altitude, I think it was about 2am before I finally passed out.

Next morning we were greeted by blue skies and perfect views all around. Time for a few photographs and a four-hour walk down the 'tourist' route to Borovets, as it turned out the cableway doesn't work on a Monday. The first section is anything but touristy and a slip here wouldn't be a good idea. It is protected by cables fixed to posts, a remnant of an old electricity supply I suspect. The one good thing about long but gradual routes off is they do tend to be easier on ageing knees. The clear day also gave us the opportunity to see our footsteps and plot our route accurately from the previous day.

It was almost 11hours walking and climbing to the summit from the top of the ski lift, we could have moved fast with a longer rope and maybe taken an hour or so less, but really, why would you want to rush a ridge like that? It was very Alpine in character, and it is very surprising that we struggled to find any information on it. Was it the first British winter traverse!?

We timed the trip to perfection, late April, as Borovets closed down that weekend. If you want a bit more life, then go earlier in the season, but you will have to ignore the ski paraphernalia on your approach. But then John tells me it's the same at the Briethorn for example. We had a real 'out-there' climb, as we knew mountain rescue was pretty limited, Bulgaria is really 'foreign' as it were, and there was no-one else on the mountain, so we knew we had to be self-reliant. We did under-estimate it in terms of gear, but used what we had to great effect, moving slowly but safely and only leaving one bit of tat on the abseil. All in all a fabulous weekend, and great memories.