Italian and German cultures do not, as a rule, have many characteristics in common – as anyone who is interested in economics, food or football well knows. This dichotomy makes the Alpine region of South Tyrol an intriguing, Channel 4-style experiment. A geopolitical Wife Swap, if you like.

A small, hilly place about twice the size of Kent, South Tyrol is an idyllic enclave of medieval castles, steepled churches, apple orchards and vineyards. An Austrian territory for eons, it has been an Italian province since the First World War, but no one seems to have told most of the half-million inhabitants. Today 70% of South Tyroleans speak German and another 5% have Ladin, a local dialect in the Dolomites, as their first language. Road signs offer you at least two, sometimes three variations, and when you walk into a shop there's always a moment of sizing up before you decide to go for a "Buongiorno", a "Guten Tag" or even a "Gruss Gott".

As a holiday destination, it sends some mixed messages, too. Should you expect somewhere ordered and efficient, or chaotic and charming? Or would South Tyrol somehow have fatally assumed the more regrettable stereotypes of all its influences? You know, no sun loungers and waiters who try to sleep with your girlfriend.

The good news is that South Tyrol has emerged blessedly unscathed from its traumatic parental tug of war. As a territory, it has always valued its independence: it has been run since 1948 by the South Tyrolean People's Party, which is free to assign 90% of all levied taxes. So while some aspects of life here are unmistakably Italian and others Germanic, it remains a place not quite like anywhere else in Europe.

South Tyrol can seem a gnarly, impenetrable place to reach, existing entirely within the Alps sung with the Austrian border to the north and Switzerland to the west, and its landscape is defined by spiky peaks and dense forests. There are now road links from Innsbruck and Munich, but most British travellers fly to Verona and proceed north for a couple of hours by rail or hire car.

This journey will be extended if you stay – as you must do – in the Pension Briol. This 13-room fairy-tale hotel is halfway up a volcanic mountain in the Dolomites, in the east of the region. First you have to reach Barbiano, a village high in the Isarco Valley; map readers be warned that there are multiple place names (here we will favour the Italian versions).

At Barbiano you leave your transport in a car park and take one of two options for reaching Briol: either a punishing 15-minute taxi-jeep ride on a rocky path up the side of the mountain or an hour-long scenic walk through Alpine pastures and wildflower meadows.

The advantage of arriving on foot is that the remarkable Briol slowly reveals itself through gaps in the trees. The mountain you are climbing is called Tre Chiese, named after three ancient churches, but is known locally as "the mountain of women". It was bought in the 19th century by Johanna Settari; she divided it up and handed it down to her 15 children (11 daughters and four sons). Settari laid down a few ground rules: most importantly, that the mountain should remain in the family and that development would be limited to simple, congruous structures. These wishes have been assiduously respected.

Briol started off in 1898 as a Tyrolean mountain refuge, but was developed into its present form in the 1920s by Hubert Lanzinger. Obviously an admirer of the Bauhaus school of design, he set out to make "a temple to the sun" at 4,300ft. The result is a stunning modernist structure of brick and wood with large windows that allow you to peer down over Val Gardena and a mountain-water swimming pool.

The guesthouse is run by Settari's great-granddaughter, Johanna von Klebelsberg, and her husband Urban, and staying at Briol feels (pleasantly) like stepping back in time. The elegant pine chairs and tables, crockery and cutlery were all designed by Lanzinger; the floorboards are spruce. There are no private bathrooms, just shared facilities on each floor and a white tin jug in your room. Dinner is announced by a cowbell, and you are brought three courses without being consulted on the menu. This is only a problem if you don't like dumplings and apricot tart; your sole decision is to pick wine from a list created by Urban, a vintner by trade. There are no TVs, just an old-fashioned games room – and don't even think about asking for a Wi-Fi password.

I had heard that the von Klebelsbergs were working with acclaimed Swiss architect Peter Zumthor, the 2009 Pritzker prize laureate, on five wooden treehouses for Briol, but Johanna seemed almost embarrassed when I brought this up. She has known Zumthor for many years, long before his recent celebrity, and the idea of the retreat being overrun by architecture groupies made her deeply uncomfortable.

Despite von Klebelsberg's protests, those with an interest in design are likely to be drawn to South Tyrol anyway. If you can bear to leave the cool and calm of Briol you can see an alternative vision of modernist living at Renon, the location of an example of a Fincube house. Fincubes are high-concept, low-energy homes built from wood and glass that are sustainable and transportable.

In the region's capital, Bolzano, there is Museion, a modern and contemporary art museum housed, since 2008, in a futurist oblong cube. Nowhere is South Tyrol's intermingling of cultures more evident than in Bolzano, a small city with the German-speaking medieval centre on one side of the River Talvera and the predominantly Italian modern quarter on the other. Museion stands in the middle, and with its transparent facade it seems like it is uniting these two unlikely cultures. Like the rest of South Tyrol, it shouldn't work, but somehow it does.

Essentials

British Airways (ba.com) flies twice daily from Gatwick to Verona from £90 return. Pension Briol (briol.it) has rooms from €89.50 per person per night for half-board. For more information on the region of South Tyrol, visit suedtirol.info

This article was amended on 20 August 2012. The original headline said: "South Tyrol: where Germany and Italy collide" rather than "South Tyrol: where Austria and Italy collide". This has been corrected. This article was futher amended on 22 August 2012 to clarify South Tyrol's
cultural heritage and geographical location.