Pranala

In Hindu temple architecture, a pranala (IAST: praṇāla) is a discharge outlet attached to the wall of the sanctum.

[5] The most common type of pranala in historical temples is the makara-pranala, which is similar to the European gargoyle.

[6] The 11th century text Samarangana Sutradhara recommends making a pranali (that is, pranala) drain all around the sanctum, with an outlet in the shape of a graha (or makara).

Vishvakarma's Vastushastra, a late 11th century compendium on the Māru-Gurjara architecture, also mentions the pranala.

[1] Aparajita-prchchha, dated late 12th to early 13th century, refers to the makara-pranala used to clear the water out of the temple's jagati (platform).

A pranala at the Brihadisvara Temple in Thanjavur
Another pranala at the Brihadisvara Temple, Thanjavur