Who first accurately calculated the circumference of the Earth?

Eratothsenes Follow the link to his very cool project
The Ancient Greeks - and they got it right, which was more than Columbus did!
The Greek mathematician Eratosthenes calculated the circumference of the Earth fairly accurately over 2300 years ago!
Eratosthenes was the first person to do this. He measured the distance netween two points and the different angles mad by the Sun - and worked out from these. His result was surprisingly accurate.