When they knocked down a wall in the corner of the patio of their townhouse they were astonished to find a small arched opening leading underground to a funerary chamber dating from the first century AD.
Within the chamber they discovered eight niches, with six of them occupied by funerary urns or chests containing what is thought to be human remains dating back more than 2,000 years.
An archaeological team dispatched by the town council to examine the site described it as “perfectly preserved” and said it was the most important discovery made in the area for decades.
Juan Manuel Román, an archaeologist employed by the council, emphasized “the outstanding importance of the discovery”.
“It’s been 35 years since a tomb was found in such a magnificent state of conservation,” he said, adding that it didn’t appear to have suffered any deterioration over the centuries since it was sealed.
“There is barely two fingers worth of sedimentation,” he added.
An initial study suggests the funerary urns are made of different limestones and glass and are sealed in protective lead casings.
Vessels associated with funerary rights, including unguentaria (small bottles used to contain perfume or oil) and glass dishes where offerings would have been made, were also undamaged within the tomb.
The walls of the chamber are decorated with a geometric grid and there are inscriptions on three of the niches, perhaps indicating the name of those interred within.
José Avilés, 39, the owner of the house, who is known by neighbours as Pepe, told local media that he was astounded by the discovery. “We never imagined when we were building an extension to the house that we should find such a thing,” he said.
“It’s all happened very quickly but our intention is to keep the chamber open, preserve it and protect it and somehow incorporate into the house,” he said.
“But we’ll have to see what the archaeological teams say,” he added.
Work immediately started by the council's archaeology department who said the artefacts found in the tomb would be closely studied and then go on display in the town's archaeological museum.
Carmona, known as Carmo in Roman times, was one of the most important cities in Roman Spain and today is home to one of the most interesting Roman era archaeological sites; the Roman Necropolis, a collection of over 300 tombs.