Grotta del Trullo, Natural cave formation in Putignano, Italy.

Grotta del Trullo is a natural cave near Putignano featuring multiple chambers with smooth alabaster walls, reddish minerals, and white crystalline formations throughout. The underground spaces display various geological structures created over thousands of years.

Workers digging a sewer trench on 29 May 1931 broke into the cavity a few metres below ground. The entrance building was then raised in the style of three joined trulli, giving the cave its local name, grotta del Trullo. A steel spiral staircase was installed from the well mouth down to about 12 m, and walkways and stairs continue to roughly 20 m below ground.

Locals call it grotta del Trullo because the entrance building was built in the style of three trulli placed side by side, and the name passed from the structure to the cave itself. The trullo serves as reception, information point and the start and end of the visit.

Visits run in small groups and begin with a steep steel spiral staircase from the entrance well, dropping about 12 m below ground level. A fixed route of metal walkways and stairs then continues to roughly 20 m depth, where the tourist section ends. The lower speleological tunnel, leading to the chamber found in 2006, is closed to the public.

The cave is the first karst cave in Puglia opened to tourists. Its entrance building was modelled on trulli, three joined on plan, which gave the cave its local name, grotta del Trullo. Below the tourist route, a 20 m descent leads to a new cave found in 2006.