Beaumont Children

It was 1966, a gorgeous Australia Day in the suburbs of Adelaide, when nine-year-old Jane Beaumont and her siblings, seven-year-old Arnna and four-year-old Grant vanished seemingly into thin air. The kids hopped a bus for what should have been a five-minute ride to Glenelg Beach, a popular spot they visited often. Hours later, they failed to return home, setting into motion one of Australia's most sensational mysteries — and even today, one of its most prominent cold cases.

Witnesses claimed to have seen the siblings on the beach playing with a tall, thin, blonde man. Jane Beaumont was spotted buying snacks (including a meat pie, which the children had never purchased before) with money she did not have when she left the house that day. A mail carrier who knew the family saw the kids walking in the direction of their home a few hours later ... but they never made it. Where did the children go? Who was the tall man? Though the case has continued to generate leads and wild theories (religious cults, a madman who may have turned the kids into a human centipede of sorts via "experimental surgery"), it remains unsolved. Needless to say, parents in Australia became a lot more protective and paranoid in the wake of this case.