While staying in Strasbourg on our Alsace trip, we decided to take a day trip up to Luxembourg. We never visited Luxembourg so this was our chance. Luxembourg is an interesting city because it contains an upper city and a lower town in the valley below known as Grund. From the upper city you get great views looking down into the lower city and vice versa. It's quite a hike up and down the cliffside to get from one part of the town to the other. It's all worth it, though, for the stunning views you get.