> 300 years is feasible from an engineering perspective while 300,000 years is not. Besides engineering, communication of that facility's purpose is also impor

> 300 years is feasible from an engineering perspective while 300,000 years is not. Besides engineering, communication of that facility's purpose is also important. You don't want a fancy storage facility becoming a tourist destination in 100k years either. Barring a massive collapse - loss of global knowledge and societal progress scenario (asteroid impact, super volcano, whatever), there's a great chance of some version of our modern languages surviving and being mostly readable to somebody on Earth born in 2312. Conveying the waste storage site's inherent danger to that person 300 years from now is fairly easy task for our current society; just as we have lots of things from 1712 that still exist and are still mostly comprehensible. We simply can't fathom how we'll communicate danger to someone ~15x further into the future than the entirety that our current civilization has even existed. Look at how much trouble we had deciphering hieroglyphics and that was only 6,000 years ago. It may not even be humans that come across it 300,000 years from now.