Heidelberg, Germany

Atmospheric Squares: Old Town is dotted with enjoyable squares, and the prettiest of them is Kornmarkt, an ideal corner to people watch and take in the city's uplifting vibe.

Literary Lineage: Heidelberg has long cast its spell on artists, philosophers, and writers — Mark Twain arrived here in 1878, intending to stay a day or two but lingering for three months and chronicling his infatuation in "A Tramp Abroad" — and scores of publishing houses, bookshops, libraries, and literary festivals call the city home. Its long dedication to the written word earned Heidelberg coveted UNESCO City of Literature status in 2014. 

Medicinal History: German scientists and doctors contributed widely to advances in Western pharmacology. At the Deutsches Apotheken-Museum (German Pharmacy Museum), located inside Heidelberg Castle, hundreds of medicines from the 18th century and the Napoleonic period are exhibited.

Heidelberg Castle: A formidable red sandstone fortress that dates back to the 13th century, “Schloss Heidelberg” rises 300 feet above the river. Some of it lies in ruins (though tidily kept), but there are plenty of lavish fairytale-like rooms to tour, as well as a cellar that's home to the world’s largest wine barrel — created in 1751, it's capable of holding more than 58,000 gallons. The castle's central Gothic and Renaissance courtyard is awesome at sunset, and during the summer, it hosts an impressive outdoor theater festival.

Ruprecht-Karls-Universität Heidelberg: Founded in 1386 and more commonly known as Heidelberg University, this is Germany’s oldest and most lauded institute or learning, counting Nobel Laureates among its alumni. The school played a remarkable role during the era of German humanism and the Reformation. Today, its more than 30,000 students — from Germany and around the globe — bring ever-fresh vigor to the city. The campus is also home to one of the best botanical gardens in Europe.

Duos With a Thirst For Romance: Couples will be swept up in Heidelberg’s allure — all the more so if they're wine or beer lovers. Great places to sip include family-owned Clauer Winery, offering rieslings, gewürztraminer, and pinot meunier and other varietials; Vetter’s Alt-Heidelberger Brauhaus, home to massive copper fermenters; and Kulturbrauerei Heidelberg AG, which serves craft beers and hearty German cuisine.

It's Popular: Almost 12 million visitors flock to cozy Heidelberg every year — mostly during the high season, summer. (Christmas season is popular, too.) If you’re a traveler who seeks a more serene ambience, time your trip to off-season months.