Bucharest began as a fortress in the 15th century, a warlike origin that set the tone for its turbulent history. It saw glory days as the summer residence of the Wallachian princes and was burned to the ground by the Ottoman Turks; then Austria-Hungary and imperial Russia fought over it for a century. After Wallachia and Moldavia united to form Romania in the mid-19th century, Bucharest enjoyed a prosperity that was reflected in its extravagant architecture, some of which miraculously survived WWII bombing and Communist building programs.

You’ll see Bucharest’s very own Triumphal Arch, which is modeled after the Arc de Triomphe in Paris, and Victoria Boulevard, lined with chic shops and handsomely restored pre-war buildings—and sites where protests brought down Ceaușescu’s regime in 1989. These days Bucharest enjoys a lively and eclectic cultural scene, hosting international arts festivals and concerts, and a measure of prosperity apparent in its busy cafés and thriving street life.

For the most dazzling stop of the day, you’ll visit the colossal People’s Palace, the second largest office building in the world. It’s certainly one of the grandest as well, filled with crystal chandeliers, mosaics, marble, gold leaf, and stained-glass windows. A remnant of the city’s communist history, the building’s original design took a team of approximately 700 architects and was inspired by Socialist Realism, Modernism, and Neoclassical architecture. Though the People’s Palace was ordered by Nicolae Ceaușescu, the last communist leader of Romania, it was not completed until 8 years after his death. The Palace now houses the Romanian Parliament and three museums, including a contemporary art museum and the Museum of Communist Totalitarianism.

Twice the capital of Bulgaria—before and after the Ottomans conquered the nation—Veliko Tarnovo climbs steep hills above the Yantra River, topped by the ruins of Tsarevets, the stronghold where Bulgaria’s kings ruled between 1185 and 1393. The remains of the great stone walls and towers that you see formed the historic heart of the Second Bulgarian Empire. History lives in this town, as a quick look at the wares for sale in Samovod Marketplace will show you: Handicrafts are all made by local artisans using ancient, medieval, or Renaissance technologies. You’ll have time to peruse the exceptional local pottery and textiles there before heading to Arbanassi, home to six amazing 17th-century stone churches, each one decorated with colorful and intricate frescoes. Learn something of the multicultural history of this fascinating town at the Ethnographic Museum and visit the UNESCO-designated Nativity Church, where murals of the Nativity, the Last Judgment, and the zodiac brilliantly blend religious and humanist iconography. At another of the churches, Holy Archangels Michael and Gabriel, you’ll hear the otherworldly singing of an Orthodox choir in a short concert. Your day’s adventure includes a traditional three-course Bulgarian lunch, complete with live folk music.

Walk through the woods of Rusenski Lom, a protected region that is home to a wide variety of rare birds, among other wildlife, to Ivanovo Rock Monastery—once an enclave of more than 40 churches and chapels that the devout built inside caves above the Lom River Valley. A UNESCO World Heritage Site, it is famous for its beautiful and well-preserved 14th-century murals.

Your next destination, the Basarbovo Rock Monastery, is the only rock monastery where monks still live and worship today. Climb the narrow rock stairway to the 15th-century cloister, which is cut into the limestone cliffs high above the Lom River, and take a look at the arresting frescoes. You’ll also spend some time in Ruse, a city with an easygoing, gracious feeling. Freedom Square, a huge open plaza, takes its name from the Freedom Monument, which soars from the center of the square; the stately Belle Epoque buildings surrounding the square attest to the city’s prosperity in the 1890s. Stroll along wide, tree-lined Alexandrovska, the main pedestrian street that links the city’s many attractive squares, encountering such landmark sights as Ruse’s grand theater, the city museum, and the first movie theater (it opened in 1896).

Your first stop is Golubac Castle, one of the best-preserved medieval fortresses in Europe, a powerhouse that has loomed over the Danube for centuries.

Later you'll visit Lepenski Vir which is one of the largest and most significant prehistoric archeological sites from the Stone Age, located on the Danube. It was once the epicenter of one of the most highly developed prehistoric cultures, with complex social relations and even rudimentary urban planning. The discovery of this prehistoric settlement has changed the image experts once had about the early Stone Age, expanding scientists’ knowledge about human communities that walked the earth millennia ago.

Take in the breathtaking landscape of Djerdap National Park, where rolling green hills rise above a stretch of calm Danube waters. We’ll set out on an easygoing hike, approximately half a mile each way, to the best vantage spot in the park: the Kovilovo Viewpoint. This spacious outlook presides over an impressive portion of the Danube that is about a mile wide.