The “Mona Lisa,” the Colosseum, Notre Dame Cathedral, Michelangelo’s “David”: Europe’s cultural treasures are world class, including some of the most beautiful and enduring objects humans have created. For some, Notre Dame’s vast interior can be a yawning bore, and the Vatican Museums on a busy day can make anyone a Roman ruin. European museums, which used to be stingy with helpful information (and almost none of it in English), have figured out that they have an international clientele. The best museums do a lot of the background study for you, with extended labels, good audio guides and fun apps for your smartphone. If you dig a little deeper, you’ll find that European museums are filled with artworks that have the sharp immediacy of eyewitness accounts. In Germany, Reformation-era paintings pump up the charisma of Martin Luther as he challenged teachings of the medieval church. In Scandinavia, vivid slice-of-life scenes show off the epic nature of the land and the psyche of a pragmatic people. Lush portraits of brilliantly wealthy Dutch traders boast of their status and success, with their ships roaming the globe and their leading city the pinnacle of European civilization. Intimate scenes of daily life — a woman reading a letter, skaters gliding on a frozen river, a maid pouring milk — show the prosperous Dutch at work and play. Rick Steves writes European travel guidebooks and hosts travel shows on public television and public radio.