Just how the Middle of the World wound up being not quite at the middle of the world is unclear.

Luis Pulgar, an administrator at the park, which is just outside Quito, the capital, said that the nearby land where the Equator runs is traversed by a ravine and that the ground there was not suitable to hold a monument, so the builders chose a different location. The current monument, built in 1979, is almost 100 feet high, topped by a globe five feet across. Raquel Aldaz, the park’s museums chief, said the site first contained a smaller monument, erected in 1936. The builders, she said, believed they were placing the monument in the correct spot, except that measuring techniques at the time were not as accurate as they are today, so they were off by a few hundred feet.

Ramiro Pontón, the head administrator of the park, which is owned by the government of Pichincha Province, said that different GPS technology can result in conflicting measurements, but that according to one of the most commonly used GPS devices, the monument is about 800 feet, or more than two football fields, south of the Equator.

The original monument was built to commemorate the 200th anniversary of the arrival, in what is now Ecuador, of the French Geodesic Mission, an 18th-century scientific expedition intended to help determine whether the earth’s circumference was greater at the Equator or around the poles.

A recent book about the mission, “Measure of the Earth,” by Larrie D. Ferreiro, said the scientists helped prove that the earth bulged at the middle and calculated the length of a degree of latitude at the Equator within 150 feet of where geographers place it today. While the geodesic mission worked in the mountains near Quito, Ms. Aldaz said there was no indication that its members visited the spot where the monument is. The park also contains an exhibition dedicated to the geodesic expedition and large stone busts of its members.

Image Credit... The New York Times

Mr. Pulgar said that about half a million people visit the Middle of the World each year, more than half of them foreigners.