Short answers, pulled from the story.
Timgad was founded by the Roman Emperor Trajan in 100 AD as a colonial city in the Aurès Mountains of Algeria. Its full official name was Colonia Marciana Ulpia Traiana Thamugadi, honoring Trajan's mother, sister, and father.
The name Timgad derives from the Berber word Thamugadi, which is the plural form of Tamgut, meaning "peak" or "summit." The first part of the city's Roman name, Marciana Traiana, refers to Emperor Trajan and his sister Marciana.
Timgad is considered one of the best surviving examples of the Roman grid plan. Its two main streets, the decumanus maximus and the cardo, remain clearly visible, along with the Arch of Trajan, a 3,500-seat theater, four thermae, a basilica, and a Capitoline Temple built to roughly the same dimensions as the Pantheon in Rome.
Scottish explorer James Bruce reached the ruins of Timgad on the 12th of December 1765, describing it as "a small town, but full of elegant buildings." He published his account in the 1790 book Travels to Discover the Source of the Nile.
The Library at Timgad was donated to the Roman people by Julius Quintianus Flavius Rogatianus at a cost of 400,000 sesterces. Scholars date it to the late 3rd or possibly the 4th century. It measured 81 feet long by 77 feet wide and is estimated to have held around 3,000 scrolls.
Timgad was inscribed as a UNESCO World Heritage Site in 1982. It is recognized for representing one of the finest extant examples of Roman grid-plan town planning.