Arena and the audience of the Colosseum were covered up with a giant sail (velarium), which was supposed to protect viewers from the sun and rain. It was attached to large columns on the Coliseum Mountain and anchored to the ground with large ropes.
On the third floor, remnants of mast openings located around the auditorium (cavea) and supporting sheets of thin sailing canvas (vela) were found. To unbutton this structure on the ropes, the natural skills of sailors from the fleet ships stationed in Misenum (now Miseno) were used. Although also known from preserved Gallic amphitheaters (Nimes, Arles), the velarium donation system is not fully understood.