These are the portals first mentioned at the epilogue of The Cartographer's Handbook, published in the second edition, published March 1st 1883. They are so-called because of the rushing sound of air, which is blowing against the atmosphere of the world on the other side
The known Wind Doors.
Jackson, Mississippi, America: This was the origin point of the Southern infection. The destination for the SteamHeart expedition. This one, along with the next two opened simultaneously on May 10th 1872.
Tehek Lake, Nunavut, Canada: This was the source of a far less wide-reaching Northern infection, and is the destination for the Wilson expedition, as detailed in Arlington.
Cairo, Egypt: It was mentioned by Carmen Santos that the third point of the pandemic originated in Egypt. This one had devastating consequences for Africa, Europe and Asia.
London, England: A much larger portal opened North of London in the spring of 1873, leading through to the world of Celador and its Duart population. This new species journeyed through and occupied London, assisting England and Wales with the routing of the Wendigo (or Barghest), whilst at the same time settling and occupying this new territory.
Missouri, America: Very few details are known about this one or where it leads, but it is apparently thirty feet up in the air and is often mistaken for a cloud.
Memphis, Tennessee, America: Located just outside the city in the wreck of the Natchez VII riverboat. This Wind Door leads through to the world of Rama.
Other Wind Doors include a temporary one in Secret Rooms glimpsed at Briar Hill by Doctor James Penrose and Private Abigail Grey whilst taking shelter at the house of Versteckt. It is not known where this one led.
In Tiger's Eye, Miguel and Hrao also saw ancient drawings depicting humanoid figures with strange weapons, emerging into Rama.
In The Princess Thieves it is mentioned several times that Wind Doors were involved with bridging the world to Hannoth from Celador, thus allowing an exodus of Akka.