Some 20 kilometers (12 miles) outside of Paraguay’s capital, Asunción, a crew of 20 excavation experts are feverishly digging for gold—some 10,000 kg (22,000 lb) of it, thought to be worth roughly $453 million. The gold, they believe, was buried over 150 years ago.

The 20 men have been digging since Friday (Aug. 2), because, it seems, of a rumor that the hefty trove of bullion was left behind in this very spot by a 19th-century Paraguayan president and military hero, Francisco Solano López. According to the rumor, López buried it during the War of the Triple Alliance between 1864 and 1870, when Paraguay fought Argentina, Brazil and Uruguay, and lost. Historical references and pseudo folklore place the treasure just outside of Asunción.

The experts, a group of locals whose affiliations are not known, claim scientific evidence that the gold is there, and believe it’s merely a matter of digging deep enough. “Satellite images tell us that the gold is in a secured trunk or coffin, and could even have been slipped into some sort of bunker,” the excavators told local news outlet Rosario (link in Spanish). “We’re very close. We already hit something. The build up of water is preventing us from rescuing the gold,” crew leader Juan Alberto Díaz said.

Indeed, water is gushing in at the now 15-meter (50 feet) deep site, and causing landslides in the suburb of Paraguay’s capital.

Have a look:

Reuters/Jorge Adorno Before the digging started, a starting point had to be chosen. Here, a worker with a metal detector walks at the excavation site.

Reuters/Jorge Adorno Soon, however, the site became a 50-foot well of excavated dirt.

Reuters/Jorge Adorno Excavation experts claim they have already hit “something.”

Reuters/Jorge Adorno Though what that is, they can’t say. The build up of water is making it increasingly difficult to dig on.