Jaffna is the centre of Sri Lankan Tamil culture, food and history — a peninsula city that only fully reopened to independent travellers after 2009, now drawing visitors for its vivid Hindu temples, Dutch fort ruins and a cuisine distinct from the rest of the island.
Jaffna's most important Hindu temple, dedicated to Lord Murugan, with a golden gopuram tower — see the Nallur Kandaswamy Temple guide.
A large Dutch-built fort (on earlier Portuguese foundations), one of the biggest in Sri Lanka, still being restored after wartime damage.
Tamil, seafood-heavy cooking with its own spice blends and dishes, notably different from Sinhalese food found elsewhere on the island.
Beyond the Nallur Kandaswamy Temple, add a ferry trip to Nainativu or Delft Island. Background: Jaffna on Wikipedia.