Onda is located in the north of the Valencian Community, in the Plana Baja region, province of Castellón. Its municipality, which with its 108.84 km² is one of the largest in the province, is located inland, only about 20km from the coast, in the intermediate zone between the Sierra de Espadán and the plain of La Plana, which extends to the Mediterranean Sea. This situation makes Onda a natural strategic point of entry to the Sierra de Espadán from the coast, which has conditioned the history of Onda and helps to understand the importance that its castle once had. Two rivers cross Onda, the Mijares river, to the north and away from the town centre, and the Sonella river, to the south and bordering the town. The Sichar reservoir, built on the course of the Mijares river, is also in the municipality. The highest peak in the municipality is the Montí, with 608 m in the municipality of Onda, as the peak is actually in the municipality of Tales and is 612 m.2 A mound of 284 m, on top of which is the Castle, presides over the population. The landscape is characterised by the presence of Mediterranean forests (pines, holm oaks, cork oaks and some strawberry trees), carob, olive, almond and, above all, citrus trees, especially oranges, to whose cultivation large areas of the municipality are dedicated.