Springfield Cryogenic Facility is a location where Abe Simpson was placed in sometime before 2041 due to an illness that didn’t have a cure for at the time. Homer explains that since it was cheaper than keeping him in nursing home, or, more than likely the case, Homer doesn’t have to deal with him as much. The entrance is in disguise as a gravestone, but it’s likely people are less to die gives to the technology at the time.