Frankfurt, the vibrant heart of Germany's financial sector, is a city of contrasts, blending ancient history with modern innovation. From its iconic skyline to its quaint cobblestone streets, there's a wealth of experiences waiting to be explored. Here are 10 must-do activities to make the most of your time in Frankfurt:   1. Explore the Old Town (Altstadt) Step back in time and wander through Altstadt, Frankfurt's charming old town. Here, the weather can transform the experience. On a sunny day, the medieval architecture of Römerberg Square shines, with the historic Römer building and its picturesque half-timbered houses casting long shadows. If rain is in the forecast, take shelter in the cozy cafes that line the streets.   2. Visit the Städel Museum No matter the weather outside, the Städel Museum offers a haven for art enthusiasts. Rainy days are the perfect excuse to immerse yourself in seven centuries of art history, from the Old Masters to modern works, ...