Tezqan was a town in Peru, South America on Earth. It was the home town of Dr. Sally Bellero. In 2035, the town was leveled by an earthquake, killing all of Bellero's family. Tezqan was rebuilt by 2045 and in that year Dr. Elizabeth Dehner, posing as Bellero, took up temporary residence in the town. (TOS novel: Strangers from the Sky)

There appears not to be a real Tezqan, Peru as of the writing of this article.