What Leonardo da Vinci invention is often described as the earliest known parachute design?

Leonardo da Vinci's parachute is often described as the earliest known parachute design.

Leonardo sketched the device in the Codex Atlanticus around 1485. His design consisted of a sealed, pyramid-shaped linen canopy supported by wooden poles. He proposed that a person could descend safely from a great height using the structure, even though there is no evidence that Leonardo tested it.

The drawing shows Leonardo applying geometry and air resistance to a practical survival problem. The idea differed from modern parachutes, which generally use flexible canopies that inflate during descent. In 2000, British adventurer Adrian Nicholas built and tested a replica based on Leonardo's measurements; it descended successfully, although he used a modern parachute for safety near the ground. The sketch is therefore important as an early theoretical parachute concept, not proof that Leonardo invented a functioning modern parachute.