Archaeologists have unearthed an ancient commercial farm in the heart of modern Rome, taking advantage of subway construction to explore deeply in urban settings.

They explored some 20 meters down (around six stories deep) near St. John in Lateran Basilica.

Rossella Rea, the dig's leader and a culture ministry official, said Wednesday that a farm business from Imperial era Rome was discovered, along with an irrigation basin measuring 35 by 70 meters (115 feet by 230 feet) near an ancient water source known as Aqua Crabra.

Notable finds included a three-pronged iron pitchfork and traces eroded in stone of a waterwheel.

Also extraordinary area well-preserved vestiges of willow tree roots and peach pits, presumably from the farm's orchard. Rea said peaches were then a pricey market novelty for consumers.