Campo del Cielo Meteorites:
wikipedia:
In 1576, the governor of a province in Northern Argentina commissioned the military to search for a huge mass of iron, which he had heard that Indians used for their weapons. The Indians claimed that the mass had fallen from the sky in a place they called Piguem Nonralta which the Spanish translated as Campo del Cielo ("Field of the Sky"). The expedition found a large mass of metal protruding out of the soil. They assumed it was an iron mine and brought back a few samples, which were described as being of unusual purity. The governor documented the expedition and deposited the report in the Archivo General de Indias in Seville, but it was quickly forgotten and later reports on that area merely repeated the Indian legends. Following the legends, in 1774 don Bartolome Francisco de Maguna rediscovered the iron mass which he called el Meson de Fierro ("the Table of Iron"). Maguna thought the mass was the tip of an iron vein. The next expedition, led by Rubin de Celis in 1783, used explosives to clear the ground around the mass and found that it was probably a single stone. Celis estimated its mass as 15 tonnes and abandoned it as worthless. He himself did not believe that the stone had fallen from the sky and assumed that it had formed by a volcanic eruption. However, he sent the samples to the Royal Society of London and published his report in the Philosophical Transactions of the Royal Society.[2] Those samples were later analyzed and found to contain 90% iron and 10% nickel and assigned to a meteoritic origin.[3]
Campo del Cielo is located in Argentina
Campo del Cielo
Location of Campo del Cielo craters

Later, many iron pieces were found in the area weighing from a few milligrams to 34 tonnes. A mass of about 1 tonne known as Otumpa was located in 1803. Its 634 kg part was brought in 1813 to Buenos Aires and later donated to the British Museum. Other large fragments are summarized in the table below. The mass called el Taco was originally 3070 kg, but the largest remaining fragment weighs 1998 kg.[4]

The largest mass of 37 tonnes was located in 1969 at a depth of 5 m using a metal detector.[3] This stone, named El Chaco, is the second heaviest single-piece meteorite after the Hoba meteorite (Namibia) which weighs 60 tonnes. However, the total mass of the Campo del Cielo fragments found so far exceeds 60 tonnes, making it the heaviest meteorite ever recovered on Earth.