https://www.gamespot.com/articles/assassins-creed-origins-discovery-tour-mode-remove/1100-6453613/

Ubisoft has announced a new game mode for Assassins' Creed: Origins, and it might not be what you expect. "Discovery Tour," as it's called, is a casual mode coming in 2018 for free that removes all combat so players can freely explore the ancient Egypt setting.

While in Discovery Tour mode, you're apparently able to walk or ride through the entirety of the game, including locations such as Alexandria, Memphis, the Nile delta, the Giza plateau, the Faiyum Oasis, and the Great Sand Seas. There is no combat, no story, and no time limits.