The first person to swim across Lake Ontario was 16-year-old Marilyn Bell in 1954, according to Swim Ontario, the sport's provincial governing body.

CNN: 14-year-old swims solo across Lake Ontario

Nyad's marathon swimming career began in July 1970, when she set the women's world record for the 10-mile swim across Lake Ontario: four hours and 22 minutes.

CNN: Nyad delays attempt to break distance-swim record

The hotel manager told me that tourists did swim in the lake, but he had not heard of anyone trying to swim across it before.

BBC: Long-distance swimming in Nepal��s glacial mountain lakes