It was definitely a once-in-a-lifetime opportunity to visit an underground station and an underground tunnel before it was built. It was just very interesting to see how it is done. They also had before and after pictures, a gallery of them, and pictures and concepts of how it's going to look. But it was just amazing to see this man-made tunnel in the middle of Frankfurt, such an engineering feat in your hometown. I don't think I'm ever going to be in an underground tunnel again in my life. So yes, it was a once-in-a-lifetime opportunity.











