Inside the beautiful new Croatian coastal resort with the longest infinity pool in Europe. Prefer the sea? From June to the end of October it is warm enough to swim here

Below me stretches a green headland with tangled trees, bordered by a clear blue sea, over which a small triangle sails.

I swim a few more meters and this soothing panorama continues. And I swim some more and some more.

I’m in Europe’s longest infinity pool, at 105 meters longer than Olympic Games pools, on the roof of the new Petram Resort in the northwestern corner of Croatia.

It’s not the only swimming offering at Croatia’s newest resort, complete with smart, simple apartment rooms (where children and pets are welcome), tennis courts, a spa and a rooftop restaurant with views over the Gulf of Trieste.

There’s a swimming pool in the garden that’s almost as big and just a three-minute walk (or hotel buggy ride) away is the silky, clear waters of the Adriatic Sea.

The pool is ‘longer than Olympic Games pools’ and is located on the roof of the hotel

There are swimming spots all along this rocky coast and the sea is warm enough for swimming from June to late October.

“People used to come here mainly to swim,” says winemaker Moreno Coronica, as we sit a few minutes’ drive from Petram, surrounded by the red earth vineyards his family has been growing for generations.

‘And then they might have a glass of wine, but now it is also a gastronomic destination.’

Indeed it is, with Michelin-style menus at gastropub prices.

Almost everything here is bilingual. This area was ruled by Italy (ancient Rome, medieval Venice, modern Rome) for about half of the last two millennia.

Ancient Rome can take some credit for Istria’s culinary successes since they introduced the cultivation of vines and olives.

Colourful: Juliet says the region’s picturesque coastal centers such as Rovinj (pictured) are well worth a visit

Above, Petram’s garden pool, just a three-minute walk from the waters of the Adriatic Sea

Excellent olive oil adorns almost every table, and I enjoy learning how to taste it properly (before the tongue, then suck air through your teeth and wait for the spices).

The Romans also left a more solid legacy: in the peninsula’s largest city, Pula (1½ hours from Petram), which is dominated by the curved, honeyed ellipse of the well-preserved gladiator arena.

The departure of the Italians when this area became part of communist Yugoslavia in 1945 turned many places into ghost towns, but some have since found a new lease on life and are just as worth a visit as the region’s picturesque seaside centres, such as the tourist attractions Rovinj.

When I arrive in Groznjan, Mozart floats out of the medieval Kastel, now a concert hall. And hidden in the small streets of flower-decorated historic houses are about thirty studio galleries. This colorful artists’ colony is small, but not rushed.

Juliet visits Motovun (photo), the best preserved Venetian fortified town in Istria

Above – the ruins of a Roman amphitheater in Pula, the largest city on the peninsula

A few hilltops away is Motovun. With a height of 277 meters and around 1,000 medieval stone steps (don’t worry, there’s a road too), this is the best preserved Venetian fortified town in Istria.

I pass the Palladian Renaissance church and its 13th-century campanile, originally a defensive tower said to have been shaken in frustration by the city’s legendary largest resident, Giant John, the subject of a nearby mural. I wander over the city walls and enjoy the view over the Motovun Forest, which used to provide the Venetians with wood.

Today it is equally appreciated – for truffles. I meet truffle hunter Nikola at the edge of the forest in Livade, the self-proclaimed ‘world center of truffles’. Black truffles, he says, are fungi that can be grown all year round, but white ones are autumnal, only wild and extremely expensive. The most expensive, a 1.5kg whopper, sold for £237,000 in 2007.

“Maybe we won’t find anything,” says Nikola, as his dog Zara starts sniffing the ground. Immediately Nikola is on his knees, his head against hers, frantically digging.

A moment later he leans back, in disbelief. In his palm is a large white truffle. It’s broken, which halves its value, but it will taste the same. But would I pay through the nose for it in a London restaurant without the pleasure of seeing the dog sniffing out?

I’d rather spend it on traveling to Istria, and having my truffle served, along with history, music, art, wine, olive oil, vast landscapes and swimming.