Mount Oeta is located on the boundaries of the prefectures of Phocis in the south and Phthiotis in the north. Its northern side displays a steep and inaccessible terrain as it descends to the valley of the river Spercheios, forming a series of deep gorges—most famous of which is that of the Gorgopotamos river—a few of which boast large waterfalls, including the Kremastos waterfall, considered the highest in Central Greece. To the east, Oeta is defined by the gorge of the Asopos (Ασωπός) river, which forms its boundary with the neighbouring Mount Kallidromo. The southern slopes of Oeta are very gentle, bordering with the mountains Vardousia to the southwest and Giona to the southeast. On its western slope, Oeta is separated from Mount Goulina by the valley of the river Vistriza (Βίστριζα), ancient Inachos (Ίναχος). Oeta has a complex hydrogeology. Limestone and flysch, coupled with a complex geomorphology, combine to create a large network of sinkholes and caverns, giving rise to many springs, small rivers, and seasonal ponds in the main plateaus, chiefly those of Livadies (Λιβαδιές), Amaliolaka (Αμαλιόλακα) and Katavothra (Καταβόθρα). Three major rivers spring forth from the mountain: Gorgopotamos and Asopos from the east, and Vistriza/Inachos from the west, all of which are tributaries of Spercheios. The streams of the southern slope flow into the river Mornos. The mountain's tallest peak, Pyrgos (Πύργος), has a height of , while the second-tallest is that of Greveno (Γρεβενό) at .