Luxembourg, which is surrounded by France, Germany and Belgium, is a major military fortress. The whole city is surrounded by various bunkers, city walls, and various World Heritage fortresses, moats, tunnels and other "risky strategic locations". With a strong historical smell of gunpowder, the whole city center is cut through by the valley. One side is the new city and the other is the old city. The old city is leaning on the canyon hanging rock. Standing in the city center, you can see the lowland fortress and the valley's towering green trees grow in the canyon. It seems to be a city. Lin is generally a sight that is absolutely invisible in other countries.~