Pleаse identify the аuthоr’s tоpic. The Greаt Wall оf China is a truly remarkable creation. At 4, 500 miles long taller than five men, and wide enough to allow at least six horses to gallop side by side atop it, the Great Wall is so huge it can be seen from space. The Wall is constructed of four-inch block made of compressed earth, stone, willow twigs, and the remains of laborers who died among the millions who worked on its construction. The Great Wall follows mountain slopes and has inclines as great as seventy degrees. The paths on the Wall are even more difficult to travel because the steps are of uneven depth, width, and height. Through much of its 2,500-year history, armies marched and camped on the Wall, keeping lookout for invaders and repelling trespasses who dared to pitch ladders to try to mount it. Today the Great Wall is a tourist attraction that brings many visitors to China. Tourists are eager to make the strenuous hike over precarious paths to take in the greatness of its size and history. What is the topic of the above paragraph?