Sjeverni Velebit

The Velebit runs a hundred and forty kilometres down the Croatian coast as a single limestone wall, and its northern section is the wildest ground in the country. Sjeverni Velebit was made a national park in June 1999 — the newest of the eight, and still the last one declared — protecting a hundred and nine square kilometres of the range's most broken terrain, high above the Kvarner on one side and the Lika plateau on the other.

At its core is Hajdučki i Rožanski kukovi, a strict reserve since 1969 and of a kind that has few equivalents in Europe: twelve hundred hectares of kukovi, freestanding karst towers and pinnacles separated by sinkholes and blind gullies, forested in the hollows and bare on the crests, with no marked paths and entry only by permit for research. It is also one of the most intensively caved landscapes anywhere. Lukina jama, found in 1991 and pushed through the mid-1990s, was measured at 1,431 metres — the deepest cave in Croatia and among the deepest anywhere; Slovačka jama, a few hundred metres away, is not far behind. The pits go down cold and vertical, and one of them yielded, at more than a kilometre below the surface, an underground leech previously unknown to science.

The park's other landmark is a piece of engineering. Between 1930 and 1933 the forestry engineer Ante Premužić laid out a dry-stone footpath, the Premužićeva staza, fifty-seven kilometres along the Velebit crest with some sixteen of them inside what is now the park, graded so gently that it crosses the worst of the karst maze at an almost constant contour — a walking route through country that otherwise refuses to be walked, built by hand and still in use with almost no alteration. It remains the reason the northern Velebit is accessible at all. At Zavižan, near its northern end at 1,594 metres, stands Croatia's highest meteorological station, staffed without a break since 1953; a hundred metres lower is the Velebit botanical garden, laid out in 1967 to grow the range's endemics — among them Degenia velebitica, the small yellow crucifer that grows nowhere else on earth and has ended up on a Croatian coin. The strict reserve joined the UNESCO transnational beech-forest inscription in July 2017.

What's worth knowing before you go

Senj on the coast is the usual gateway, with the mountain road climbing to Oltari and on to Zavižan; the road is unpaved in places, closed by snow from roughly November to May, and the season is short. Karlobag and Jablanac give the southern approaches. There is no through public transport — a car or an arranged transfer is effectively required — and huts along the Premužić trail must be booked. The bura here is the strongest in the Adriatic and can arrive without much warning at any season.

The connoisseur's walk is the Premužić trail itself from Zavižan south to Alan over two days, sleeping at a hut on the crest: the path threads the edge of the strict reserve with the towers of the kukovi rising on the inland side and, whenever the ridge opens west, the whole Kvarner archipelago spread out a kilometre and a half below.