In 1989, anthropology student Piergiorgio Castellani bumped into Keith Haring while on vacation in New York City. The famously approachable Haring invited Castellani to visit his studio, and there they hatched a plan for a mural on a church wall in Pisa. 

Haring usually finished murals in a day but this one took four days, with the aid of students and a local paint company that provided free materials. The piece is among the artist's last public works before his death from AIDS in 1990.

The resulting artwork on the Church of San Antonio is the largest public mural in Europe, measuring 10 meters high by 18 meters wide. The theme of the painting is world peace, as suggested by the title "Tuttomondo," which translates to "All World."

Each of Haring's figures represents a different aspect of peace—for example, a woman holding a baby shows maternity, human scissors cutting the head off a serpent show triumph over evil, men with dolphins represent humankind's relationship with nature. The viewer is also represented by the yellow figure walking toward the famous Leaning Tower.