Urartu was an early first millennium BC kingdom located in the Armenian highlands. Thanks to its animosity with Assyria, it had militaristic society and is thought to be the first kingdom to convert form bronze to iron weaponry leading Assyria to quickly follow suit. The kingdom is also know for an aqueduct, the Channel of Semiramis, a remarkable engineering feat for it's time. In modern times Urartu was unknown until the mid 1800s. Much of its history is now well documented but as of this writing the story of its beginnings and disappearance are still unclear.
—David Foss