The Medieval Bridge in the town of Estella. Estella is the most important town in the western half of the central region of Navarra province. The nearly 13,000 inhabitants live on both sides of the Ega River, one of the Ebro River's main tributaries. The land is a mixture of vineyards and orchards and truck farms. Because of its location at the confluence of cattle and sheep farmland of the North and cropland of the south, Estella's economic base is commerce. Navarra, Spain.