The Wano Country is a nation in the New World. It is a country not affiliated with the World Government. The Wano Country follows a policy of isolationism, meaning that contact with outsiders such as pirates and other countries is prohibited. Leaving the country’s borders is also considered a crime.
As the Poneglyphs are considered indestructible, the fact that the Kozuki Family of Wano Country was able to not only create, but also shape and carve them, gives a small insight into the potential technology and abilities they had.
Wano Country has its own warriors, the samurai, who are swordsmen so strong that not even the Marines go near them. It was first mentioned by Hogback, as Ryuma was from there.