The Longest Building I Have Ever Seen
It is totally windowless and stretches for at least a mile, although it seems to defy laws of space-time so it may be longer or shorter than that. From certain angles the building's length actually converges perfectly on a vanishing point. As I walk alongside the building I can only imagine it as a thought, a single orthogonal receding to infinity.

This is great. I would have been freaked out by the sidewalk as well.