Which is the only building from the Earth, visible from the Moon?
To piggyback on the last answer, there are persistent rumors that the Great Wall is visible--I love that pohnpei referenced Snopes. It is a great website to check all those "hard to believe" items that people tell as if they are true. Snopes does an excellent job of checking out those rumors, particularly ones that spread so quickly, courtesy of the internet. If it sounds too weird to be true, there's a good chance it isn't true.
Now, if you wanted a funny answer to your question, you could say that the lunar landers, which are still sitting on the moon, are visible when you are standing on the moon!
There is no building on Earth that is visible from the moon. In fact, there is no structure of any sort that was made by human beings and is visible from the moon.
The moon is 237,000 miles from Earth (this is an average distance). From that distance, Earth is only visible as a sphere with various colors.
It is generally said that the Great Wall of China is the only structure visible from space. However, it is not visible from the moon. Instead, it and many other structures, are visible from low Earth orbits such as that in which space shuttles travel.
There is no human made building visible from the moon. Probably the question occured coming from the legend claiming that the Great Wall can be seen from the Moon, with the naked eye, legend which was launched by Richard Halliburton's, in 1938 in the book "Second Book of Marvels", long before the earth to be seen from the outer space.
The only condition for the Great Wall of China to be seen from outer space is that the observer to be placed at the Earth's orbit, which is a low orbit that allows to other buildings also to be viewed from space.