These African-inspired artworks were created for an adventure, The House of Bone and Amber, for the tabletop RPG Spears of the Dawn (from Sine Nomine Publishing). They are part of an art pack released into the public domain (and available for download from here).

This set is by Ejiwa Ebenebe, Luigi Castellani, Miguel Santos, Mohammed Agbadi and Pamela Ngouoghe and depicts:

• A stone pyramid in the jungle that three adventurers are entering.
• A king with his two female bodyguards, on his throne.
• A border of bones and amber.
• A marketplace where fruit and vegetables are for sale.
• Three heavily armed adventurers are underground. The leader bears an axe and a torch.
• A woman with bright clothes and a longspear stands in the savannah.

The publisher writes:

The files in this collection are from the hands of Ejiwa Ebenebe, Luigi Castellani, Miguel Santos, Mohammed Agbadi, and Pamela Ngououghe. All of them are released into the public domain, free for use in personal or commercial projects. As a matter of courtesy, I would request that you leave their names attached to the file names and keep this collection together when you redistribute it so that end users can be confident that the art really is in public domain.

If such is impractical, you should leave a note with the files advising that the art was released on April 22, 2013, by Kevin Crawford acting for Sine Nomine Publishing. While you are under no obligation to do so, it will help give uncertain future users some reference as to when and how exactly the files entered the public domain.