Zagreb, Istria, and Kvarner Itinerary
Zagreb makes an excellent starting point if your trip is meant to cover western Croatia in a week. You'll get the mountains and the seaside, city and countryside, and a first-class Roman ruin. This itinerary is best done by car, but it can be done (perhaps a bit more slowly) by train and bus.
Day 1: Zagreb
Zagreb can best be explored on foot. Begin at the massive Trg Bana Jelačića and check out the statue of Ban Josip Jelačić, hero of Croatian resistance to the Austro-Hungarian empire. It's an imposing figure on an imposing square. From here walk to the funicular and head to the Gornji Grad (Upper Town). Stroll around the castle area and visit the Croatian Historical Museum. You'll get a glimpse of Croatia's recent history, including the controversial nationalism of the 1990s. From here, head back down to the Lower Town and check out Ilica, Zagreb's modern high street. Spend the night here.
Day 2: Plitvice Lakes
The next morning head south toward the coast, getting off the highway in Karlovac in the direction of Plitvice National Park. Plitvice is a naturally occurring water world, with cascading pools and waterfalls connecting each other. This is one of Croatia's biggest tourist sites and has been for years, so the park is well protected and organized. Consider getting a map and exploring the lakes, which cover about 300 square km (186½ square miles) on your own. The park is well marked, but the guided tours only take you to the highlights. Relax in the evening when the tour buses have gone home and spend the night here at a nearby hotel.
Day 3: Rab Island
Drive to Rab Island from Plitvice, descending down the Velebit Mountain to the eastern Kvarner coast and catching a ferry to Rab, one of the bay’s most beautiful islands. Once there, take in the sights of the medieval stone town of Rab, renowned for its history, coast, and Mediterranean herbs. Also take the opportunity to visit one of Croatia’s top wineries, where you can also spend the night. If you still have the energy, take a ferry from Rab to the island of Krk and enjoy the cliff-top town of Valbiska, home of the žlahtina white wine.
Day 4: Rijeka and Opatija
Take the ferry from Rab or the bridge from Krk and head out to Opatija, briefly stopping in the city of Rijeka for a stroll down the pedestrian zone Korzo. Once you see the palm trees lining the streets of Opatija, you'll see this is a place for winding down, Habsburg-style. Choose one of the atmospheric, turn-of-the-century hotels for a little slice of nostalgia and settle in with a good book. Should you visit in winter, you'll find the weather downright Mediterranean. Take time to stroll along a part of the 12-km-long (7½-mile-long) promenade that zigzags along the sea. If you get antsy for more seaside diversity, plan instead to leave Opatija and catch the Istrian side ferry to the islands of Cres of Lošinj. The islands—with their attractive Venetian town squares—have a different character altogether.
Day 5: Pula
From Opatija or Lošinj head south or west, respectively, to Pula and spend a part of the day exploring the incredible Roman amphitheater. This is one of the best-preserved sites in the Roman world. After walking about the Roman forum and amphitheater, as well as Napoleon’s fortress on the top of the hill, take a boat to the Brijuni Islands for the afternoon and see the zoo and tropical gardens that Tito designed. Drive the short distance to Rovinj for the night.
Day 6: Rovinj and Poreč
Wake up to the beautiful limestone architecture of Rovinj before exploring the Venetian houses and Church of St. Euphemia in the morning. From there, stop off at one of the many fine wineries en route to Poreč, another Roman-meets-Venetian-meets-Habsburg seaside gem. Check out the St. Euphrasius basilica, one of the most important remnants of Byzantine art on the Adriatic. Spend the night at one of the many fine hotels.
Day 7: Motovun and Zagreb
Head back to Zagreb via the Istrian interior. Drive east toward Pazin, stopping in the medieval hill towns of Motovun or Grožnjan for lunch and breathtaking views. These medieval villages are in the heart of truffle country, so keep your eyes open for some fresh goods to bring home. Continue northeast toward Zagreb on A6, possibly stopping at the mountain town of Fužine for the famous cherry strudel with views of Lake Bajer.