Alba

The citadel at Alba Iulia was built in the first half of the eighteenth century in the Vauban idiom — the French bastion system that replaced medieval walls once artillery made them obsolete — and it was laid out as a seven-pointed star with angled bastions covering every approach. That geometry is the whole interest, and it is a shape you experience by walking rather than by looking: the ramparts run for kilometres, the angles cut back and forth, and the ditch and outworks between them make a landscape rather than a wall. Six monumental baroque gates punctuate the circuit, the third of them the most elaborate, carved with figures and reliefs and forming a genuine ceremonial entrance. Inside the enclosure the ground is unusually open for a fortified town, holding a Roman Catholic cathedral begun in the twelfth century and the oldest in Romania, a much larger Orthodox cathedral from the early twentieth, a university, several museums including one in the former officers' quarters, and long lawns. Restoration over the past two decades has been thorough, occasionally to the point of looking new. It is free to enter and walk, and it is at its best early or in the evening when the light rakes across the bastions.

An hour into the mountains, Roșia Montană is a mining landscape rather than a monument, and it is UNESCO-listed for what is underground. Roman engineers drove galleries into the mountain here to follow gold-bearing veins, cutting by hand with hammer and chisel and using fire and water to crack the rock, and they left tunnels with a distinctive trapezoidal cross-section — wider at the base, narrowing towards the roof — running for kilometres through the hill. Several stretches are stabilised and open with a guide, and walking into a passage that was cut by hand nearly two thousand years ago, still carrying the tool marks, is an unusually direct kind of contact with the past. On the surface, the village sits among the spoil and the workings of every later era of mining, with a museum, wooden houses and a landscape that is beautiful and visibly worked. It is a quiet, slightly melancholy place and it takes half a day including the drive. Go with a guide; the site is scattered and the interpretation is most of the value.

Deeper into the Apuseni, the Scărișoara cave contains a permanent block of ice estimated to be several thousand years old and among the largest underground ice bodies known — it survives because the cave's shape traps cold air in winter and keeps it from flushing out in summer, so the chamber acts as a natural refrigerator. You reach it by descending a large collapsed shaft on stairs, and the ice floor and columns are lit below. It is genuinely cold and the descent is steep, so take a jacket and proper shoes regardless of the weather outside. The road up is slow and, in parts, rough. The wider Apuseni around it are karst mountains full of gorges, sinkholes and further caves, with scattered farmsteads at surprising altitude and very few visitors — the Cluj guide covers the range as walking country from its northern side, and this county gives the southern approaches. Elsewhere, Rimetea is a village of uniformly white houses beneath a pale limestone crag, one of the most photographed in Transylvania and deservedly so, and the Târnave hills to the east are a serious wine region.

Alba sits between the Saxon towns of southern Transylvania and the western mountains, which places it plausibly on the main arc rather than off it — the trip-planning guide sets that arc out, and this county fits between Sibiu and Cluj without a detour. That makes the citadel an easy half-day stop on a driving day, which is how most itineraries should use it. The mountain sites are a different proposition: Roșia Montană and Scărișoara are each the better part of a day once the roads are counted, and doing both properly means a night in the county. Alba Iulia itself has enough accommodation and eating to make that comfortable, and it is a pleasant, low-key town outside the walls as well as within them. The northern end of the Transalpina, the higher and less famous of Romania's two great mountain roads, begins in this county and is a summer-only proposition. Season: late spring through early autumn for the mountain sites, since the roads are poor in wet weather and the higher ones close; the citadel works year-round and is atmospheric under snow.