At first glance, this Croatian port town on the Aegean Sea seduces the eye with white stone buildings and red-tiled roofs, which glow against the bright blue of the sky and the Mediterranean Sea. As you wander down Split’s narrow streets, you realize that the buildings around you span two millennia, and you find yourself staring upwards, picking out architectural details from the Roman era, the Middle Ages, and the Belle Epoque.

Whether you’re visiting Split at the peak of its bronzed-beachcomber summers or during its moody gray winters, Croatia’s second-biggest city exudes a relaxed vibrancy. The shops and galleries along Marmont Street (Marmontova Ulica), as well as its seafood market, are bustling no matter what time of year. In the warmer months, locals and visitors alike while away the afternoon at the bars and cafes flanking the beach at Bačvice, or settle into open-air restaurant tables along the Riva, the city’s seaside promenade, for a leisurely dinner and plenty of crowd-watching.

The mild Mediterranean climate of the Dalmatian Coast brings plenty of visitors to Split. Like most of the region, winter is gentle here, though no one’s shimmying into bathing suits for a long day on the waterfront — the regular rains and winds green up the hillsides and keep locals indoors. April ushers in a flower-filled spring, and the whole town turns out for Krnjeval (Mardi Gras), celebrating with masked balls and parades. From late May through early September, the dry heat begins. With little rain and temperatures in the 80s and 90s Fahrenheit, Split’s beaches and tourist attractions fill up, and the pleasure boats on the sea proliferate. Croatians and foreigners alike descend on Split in July and August for the Summer Festival, when some of the city’s most scenic sites host open-air concerts and ballets. If you’d prefer to see a more serene side of Split, book one of the area’s vacation rentals for mid-September through October, when the water is still warm, the days are still sun-drenched, but the crowds have gone.

Tour Diocletian’s Palace

Few Roman sites from 1,700 years ago have the immediacy of the spectacularly preserved Diocletian’s Palace. Built for the emperor back when Split was a village on the outskirts of the more populous Salona (itself now in ruins), Diocletian’s fortress and imperial residence has been absorbed into the surrounding houses and shops. You will shuttle back and forth through the centuries as you wander through the ancient Cathedral of St. Domnius, arched passageways and gates, and the peristyle (central courtyard). Afterward, head to the Archeological Museum to peruse hundreds of Roman artifacts.

Take Some Island Time

You could spend a full year exploring the 1,200 islands off the Croatian coast. If you don’t have a year, take a ferry to Hvar or Brač, two of the biggest, not to mention the easiest, to get to from Split. Hvar draws the internationally rich to its azure bays and graceful villas, and you can wander around the medieval city of Hvar or escape in a car to more remote towns and beaches. On Brač, vineyards and olive groves stripe the mountainside on Vidova Gora, which you can summit by foot in just a few hours, cooling off afterward on Golden Horn Beach.

Climb Marjan Hill

Split is situated on a peninsula that juts into the Aegean, and an expansive natural preserve covers its western tip. A large hill divides the park from the residential neighborhoods on its east flank, and as you climb you’ll pass open-air cafes, a Jewish cemetery, and centuries-old chapels. Many locals treat Marjan as an open-air gym, and you’ll likely spot runners sweating up the steps and climbers feeling their way along the rocky bluffs. If you crest Marjan Hill and head back down on its north side, you’ll reach pine-shaded beaches suited for contemplating the sea rather than stretching out a towel.