Its demure appearance is deceiving: This unassuming city located in the Småland region of southeast Sweden played an important role in Swedish history. This once-fortified city hosted the signing of the Kalmar Union treaty which brought Sweden, Denmark and Norway under one monarchy in 1397. With a photogenic castle, a rebuilt 17th-century old town, a labyrinth of cobblestoned alleys and an imposing Baroque cathedral, Kalmar may seem like a port city whose prime time was in the past, but it seamlessly merged medieval history with late-19th-century industrialism and now modern technology. For a modestly sized port city, Kalmar has a major institution of higher learning—Linnaeus University—and hosts a research facility for Nordic telecommunications giant TeliaSonera. The city is also a model of sustainability and green living, like much of the rest of Sweden. Kalmar actively promotes biking culture and has installed an eco-friendly charging station for electric vehicles; it plans to supply all its energy needs with biogas by 2030. To its east lies the island of Öland with its temperate climate—a popular spot where Swedes steal away every summer for in-country vacations.