Yet life is far from gray in this part of the world. Wander the pedestrian-only areas in Belgrade, and take in the vibrant Serbian cafe culture. Look past the Soviet-style apartment buildings in Bulgaria, and appreciate some of the few pieces of communist sculpture that still stand. Gawk at gorgeous frescoes within Romania's Orthodox churches and monasteries, even as you marvel at the people's resilience. And pencil in several days to explore the beautiful 19th-century architecture and definitively 21st-century nightlife of Budapest.
Above all, be prepared to learn. After a Lower Danube cruise, you can't help leaving Eastern Europe with increased knowledge of the region's tumultuous past -- and understanding more of its challenges going forward. My fall 2012 cruise occurred on the River Splendor with Grand Circle Cruises, but most river cruise lines make similar trips, including Uniworld, Vantage, Viking, Tauck, Avalon and AMAWaterways. Click through this slideshow to see what you've been missing.