The four explorers of the Dark Dynasty (and possibly Wu Ling)
According to Pirates of the Caribbean: On Stranger Tides — The Visual Guide, Sao Feng's map is the Mao Kun Map, constructed by "four explorers" sent out during the "time of the Dark Dynasty" to locate spiritual realms and "legends of the land beyond death", including
- The Farthest Gate
- Davy Jones' Locker
- The Fountain of Youth
The map eventually found its way into Sao Feng's hands. Some more detail is found in a certificate accompanying a version of the map that was sold in promotion for the theatrical release of At World's End:
This certificate claims that, between the four explorers and Sao Feng, the map had also belonged to Wu Ling, who made
journeys to the mysterious gates of the afterlife.
Since the four explorers actually mapped Davy Jones' locker, they had clearly been there and subsequently exited it. The description for Wu Ling is less certain, as it is does not indicate which "gates" he visited.
An incursion in and out of Davy Jones' locker had been made by four unnamed Chinese explorers, during expeditions at the time of the Dark Dynasty. Additionally, Wu Ling, a Chinese navigator before the time of Sao Feng, had possibly entered and exited the locker.
The Mao Kun Map of Pirates is a reference to the actual Mao Kun Map commissioned by the Ming Dynasty, which was the result of navigator Zheng He's expeditions to far-off lands.