Needle, Thread, and Knot is a two-part sculpture created by Claes Oldenburg and Coosje van Bruggen. The work is located in Piazzale Cadorna, a crucial transportation hub in Milan due to the presence of both the Milano Nord Cadorna station and the Cadorna metro station.

The 18-meter-high structure is composed of a stainless steel needle and a self-supporting fiberglass thread 50 cm in diameter, which wraps around the needle from the eye to the street, culminating in a fountain with a 3-meter-circumference knot. The entire structure weighs approximately 20 tons.

The basic idea is that of a train entering an underground tunnel. The fact that the sculpture is divided into two parts, ideally reunited underground, is a reference to the subway, the means of rapid travel within the city: the thread, in fact, has the same identifying colors as the three Milanese lines in use at the time.