Assassin's Creed Shadows ... versions of full countries like we saw with Greece and England and Assassin's Creed Odyssey and Valhalla. It's also possible that this could be one map in the game ...

Completing all four of the tombs added via Assassin's Creed Valhalla update 1.4.0 gets you a full set of armor. The Fallen Hero armor set is one of the best in the game, and it looks cool to boot.