Walk a few blocks back from the seafront and you come to the largest Roman baths in the Balkans. They are also among the four largest Roman baths anywhere in Europe, partial walls still standing two stories high, the brick arches of the bathing chambers open to the sky. Built in the second century AD when this was Odessus in the Roman province of Moesia, they covered seven thousand square meters and could serve hundreds of citizens at once. The hypocaust system that heated the floors is still visible in places. So is the careful brickwork that survived the Visigothic raids, the Slavic migrations, the Bulgarian conquest of the seventh century, and roughly 1,400 years of people quarrying the bath complex for stones to build their own houses.

The Varna Archaeological Museum, housed in an ornate former girls' school, holds what is sometimes called the oldest worked gold on Earth. It came from a chalcolithic necropolis just west of the city, accidentally found by an excavator operator named Raycho Marinov in 1972. Hundreds of graves dating to roughly 4,500 BC, containing thousands of gold artifacts crafted by people who lived in this region nearly seven millennia ago. The museum displays many of them in dim cases — diadems, bracelets, beads, the contents of grave 43, which once held the body of a man buried with more gold than anyone else in the prehistoric world. Tourists who come to Varna for the beaches often skip the museum. The locals know the gold is the more remarkable thing.

By 1878, when Bulgaria emerged from five centuries of Ottoman rule, Varna had eighteen working mosques. Today only two of those Ottoman-era mosques survive, one of them still open for prayer. There are two old synagogues from the Sephardic and Ashkenazi communities — the Ashkenazi one is built in Gothic style and is being restored; the Sephardic one is dilapidated. There is the metropolitan Dormition of the Theotokos Cathedral, the seamen's church of Saint Nicholas, an Armenian Apostolic church, two Roman Catholic churches, an Evangelical Methodist church that hosts organ concerts, and a small Buddhist center. The seventeenth-century Theotokos Panagia church is built on the site of an earlier church where, possibly, the Polish-Hungarian king Władysław III is buried after his death at the Battle of Varna in 1444. The city has spent its entire existence as a meeting point, and it shows.

Hot mineral water bubbles up along the city beaches at temperatures up to 55 degrees Celsius — sulphurous, faintly medicinal, used in spa pools and public showers since antiquity. The two-kilometer Asparuhov bridge, fifty-two meters above the bay, draws bungee jumpers. North of the city stretch the resort districts of Golden Sands and St. Constantine, the kind of beach hotels that fill with Bulgarian, Russian, and German vacationers from June through September. South lies the strange wind-eroded landscape of Pobiti Kamani, the Stone Forest, where columns of weathered limestone rise from sand like ruined pillars. Inland is the medieval cave monastery of Aladzha, cells carved into a cliff. Varna is a Black Sea port city that has been many things across many centuries, and on a summer evening when the seagulls are loud and the planetarium is lit up against the dark, all of those layers feel like they are happening at once.