Rivers of Gondor - Definition

In J. R. R. Tolkien's fictional universe of Middle-earth, there are two common lists of rivers of Gondor.

The Seven Rivers of Gondor are the following:

1. The river Lefnui,
2. The river Morthond,
3. The river Ciril,
4. The river Ringló,
5. The river Gilrain,
6. The river Sernui,
7. The river Anduin.

The Five Rivers of Lebennin are the following:

1. The river Anduin,
2. The river Celos, which started in the White Mountains and became a tributary of-
3. the river Sirith, which met Anduin at Pelargir,
4. The river Sernui (also spelled Serni), which began in the plains of Lebennin and met the Bay of Belfalas north of Ethir Anduin at the city of Linhir, and
5. the river Gilrain, which started as two unnamed tributaries in the White Mountains, and flowed south meeting the Sernui at Linhir.

The river Poros was the effective southern border of Gondor during the later Third Age.