I think this misses the spirit of the question. One could argue the space station is far more impressive than a grand cathedral. Our engineering disciplines ar

I think this misses the spirit of the question. One could argue the space station is far more impressive than a grand cathedral. Our engineering disciplines are far, far more advanced. Many cathedrals are sublime nonetheless. In fact, maybe even because they were built at a time so much more primitive than the present. So, what's the best digital monument we could build, given the present knowledge and practices of our best practitioners?