Short answers, pulled from the story.
Numantia was an ancient Celtiberian settlement built on a hill called Cerro de la Muela in the current municipality of Garray, Soria, in Spain. It was an Iron Age hill fort, known in Roman terminology as an oppidum, that controlled a crossing of the river Duero.
After twenty years of inconclusive conflict with Numantia, the Roman Senate assigned Scipio Aemilianus Africanus the task of destroying the city in 133 BC. The war had included the humiliation of 20,000 Roman soldiers surrendering to the Numantines in 137 BC.
Scipio Aemilianus surrounded the city with a nine-kilometre barrier of towers, moats, and impaling rods. After eight months of famine, most inhabitants chose to die by their own hands rather than surrender. After thirteen months total, a few hundred survivors burned the city before giving themselves up.
Tiberius Gracchus served as a young quaestor during the 137 BC campaign, when 20,000 Roman soldiers were surrounded by the Numantines. He negotiated a peace treaty that saved the Roman army, performing an action normally reserved for a legate of much higher rank.
The ruins of Numantia were declared a national monument in 1882, following Eduardo Saavedra's identification of the correct site in 1860. The German archaeologist Adolf Schulten began excavations in 1905 that located the Roman camps around the city.
The Horse of Numantia, also called the Caballito de Soria, is a copper fibula discovered during excavations in the early 1990s. For the Numantines it represented Epona, the goddess of horses, and signified wealth and social status. Today it is the most iconic symbol of the province of Soria.