The following page of the guide contains the information on the tombs located on Hephaistos Islands. The area consists of islands Lemnos and Thassos.
There is only one tomb on Lemnos. It is located in the eastern part of the island.
Location of the tomb: Eastern part of Lemnos
Walkthrough: This tomb is linear. Just follow the path until you reach a wooden shelf. Pull it to your side to open a passage.
After you move the shelf, climb the stairs. You'll find a hole in the floor. Fall through it and proceed along the path until you find the stele and a chest.
In the chest you will find a golden axe with quite decent stats. Activation of the stele will complete the tomb.
There is only one tomb on Thasos. It is located in the central part of the Island, right next to the city.
Location of the tomb: Center of Thasos island.
Walkthrough: This tomb is very short and easy to complete. You just have to break the vases blocking the passage; once you're on the other side, you'll find yourself in the room with the stele. Activate it to complete exploration of the tomb.