The Amber Seal was an artifact discovered by Sir Richard Byrd.
The Amber Seal was a tablet that Sir Richard Byrd took from the Amber Room as proof that he had hid the Room somewhere in the North Pole. On the back of the Seal are coordinates that lead to the location of the Amber Room.
Russian mob leader Mykola Rusnak came in possession of the Amber Seal and planned to sell it in a black market auction at the Vokolov Castle. Michael and Rose Doughty sought to purchase the Seal so they could find the location of the Amber Room. However, Nathan Drake and Chloe Frazer stole the Seal before the auction the next day. Drake and Victor Sullivan were then captured outside the Castle by the Doughtys and forced to decode the coordinates on the back of the Amber Seal. Drake purposely gave the siblings false coordinates a few miles away from the actual location of the Amber Room in Agartha, the mythical city at the center of the Earth. At the North Pole, the Doughtys realized Drake gave them the wrong coordinates and forced him and Sully to fly to the correct location.