When you travel to Europe, it can feel as though you’re entering a time machine—history stretches back for thousands of years, and its remnants are found everywhere. For Europeans, 1776 seems like yesterday. They think nothing of living in 500-year-old houses, strolling along thousand-year-old streets, and passing between columns where Aristotle and Julius Caesar once roamed. Many of Europe’s historic structures were built to impress; there’s no book learning required to feel a sense of awe when you enter the <a href="http://www.fodors.com/world/europe/spain/andalusia/review-101430.html">Alhambra</a> in Granada or <a href="http://www.fodors.com/world/europe/italy/rome/review-90079.html">St. Peter’s Basilica</a> in Rome. Nonetheless, a little knowledge goes a long way. The descriptions found in our destination guides will give you an overview of each sight’s essential facts and historical highlights. The amount of further study you can do is nearly limitless. Some travelers enjoy zeroing in on one particular sight from their itinerary, researching it in depth before they leave home, then dedicating a day (or more) to exploring their chosen destination. If research isn’t your thing, you might instead try hiring a tour guide—a good one can bring a pile of ancient stones to life.