The Zanarkand we know in FFX universe has two faces: the real Zanarkand that was destroyed by Sin 1000 years ago during the Machina War, and the Dream Zanarkand created by the Fayth. Lenne is a resident of the real Zanarkand, which we can assume to be her hometown. In spite of being a city of summoners, Zanarkand was quite advanced technologically, at least in appearance: the high rises visible from Zanarkand Ruins are all we need as proof.
Zanarkand Ruins was treated as a holy place throughout FFX, but was almost turned into a tourist attraction by Cid in FFX-2. Yuna and party would learn a great deal of Spira's history here through Maechen the sage, including Maechen's one-time encounter with Lenne and her connection to the present world.