The Mounted Warrior Stable is an Iron Age Military Building. It is where a player can train Mounted Warriors, the fast unit of the age. It is the third unlocked military building of the age. In order to construct the Mounted Warriors Stable, a player needs to have unlocked the Military Tactics technology.
For more information visit the Mounted Warrior page.
In update 1.85, the graphic of the Mounted Warrior Stable was reworked.