1. The Great Wall of China is 8,852 km or 5,500 miles long, and it is the only man-made land mark on Earth that can be seen clearly from a satellite up in the space.

2. The Great Wall stretches for thousands of miles, like a gigantic dragon winding through mountains and valleys.

3. The Great Wall is more than 6,000 kilometers long and is the longest wall in the world.

4. It starts Shanhaiguan in the east to Jiayuguan in the west. Its so long that nobody can walk from the beginning to the end.

这些句子都以不同的方式表达了长城的壮观和长度，可以根据具体的语境和表达需求选择合适的句子。