The peninsula is the northernmost region of the Island of Sri Lanka. It is in close proximity to the sub-continent of India and separated from it by the Palk Strait and the Bay of Bengal. The peninsula is virtually an island; only the narrow causeway known as Elephant Pass connects Jaffna with the rest of Sri Lanka. (It is said that Elphant herds walked through the shallow lagoon here to move towards Jaffna, and infact India, in ancient times when a land bridge existed.)

Jaffna is low lying; much of it covered by shallow lagoons, there are a number of interesting islands dotting the shoreline. Most of the area is dry and sandy, and the most common tree is the palmyra palm with its elegant fan-like fronds. Locals here tap it for toddy. The flat Jaffna Peninsula is made of limestone, unlike most other parts of Sri Lanka.

It is in the peninsula that the orginal settlers of the country landed at a location called "Thambapanni". Jaffna continued to be the capital of the Northern Kingdom throughout documented history. It has a rich history and cultural significance when considering the history and culture of Sri Lanka.

It is some times said that the local name of Jaffna "Yapane" constitutes two words- Yaha and Pane, which could mean "good water" since many trading vessels would dock at the ancient habour of Jambukola to stock up with fresh water from the natural springs at Keeri Malai.