Zeta is not the largest Montenegrin river, but the mediaeval state was named after it – Zeta. Its source is in the Nikšić field, then flows underground for a part of its course, then in the Bjelopavlić valley it is a calm and meandering river, just to reach the ruins of erstwhile Dioclea, present Podgorica, and form a confluence with Morača. Its course is 89 km long.
The longest Montenegrin river is Tara. Other major rivers are Piva, Ćehotina, Zeta, Morača and Bojana. Their turquoise-green colour and deep canyons the run through are part of the typical Montenegrin scenery. The Montenegrin relief features four areas: the coast, the deep karst, the lowland of the middle Montenegro and its highlands and plateaus. The highest peak is Zla Kolata (2,543m) on Prokletije mountains, then Bobotov kuk (2,523 m) on Durmitor, while Orjen (1,894 m) rises on the Coast. Orjen mountain is among the places of the most precipitation in Europe. In the north there are glacier lakes – Plavsko, Biogradsko, Šasko, Crno jezero (one of the 18 glacier lakes on Durmitor, collectively called as the mountain eyes). The biggest is Lake Skadar, being the biggest in the Balkans and the largest cryptodepressions in Europe (some parts of the lake are below the sea level).