

Ta4HfC5 can withstand temperatures of 4215 Kelvin. There is one possible metal compound for this: Tantalum hafnium carbide (Ta4HfC5). That's higher than the melting point of Tungsten. The time that it would have taken for nature to destroy Aperture Science would be thousands of years, because Aperture Science equipment can withstand temperatures of 4000 degrees Kelvin. So, we turn to one possible explanation: Nature. But since Chell does not die of radiation poisoning during Portal 2, we can safely assume that this is not the case. But this could not have happened, because it would have incinerated everything, or at least left it in a state of disrepair and radioactive hell. Aperture Science is known to use alternate dimensions, so it's not at all impossible for them to have utilized multiple dimensions to make the facility infinite), so it would have taken a destructive force equivalent to a nuclear explosive device. The facility is huge, at least 5000 meters deep (most likely deeper. However, in Portal 2, the facility is completely trashed, as if somebody came in smashing every object they could find. In Portal, the facility has a few broken things, such as pipes, however we can assume that this is merely because of the carelessness of Aperture Science.

Aperture Science is located in Upper Michigan.
