The Ilocos Region is a pretty big area on the North Western side of Luzon facing the South China Sea, made up of 4 provinces, Ilocos Norte, Ilocos Sur, La Union and Panasinan.
I?m not sure you could do the area justice by narrowing it down to 3 tourist spots in the Region, but if I was to pick my one favourite spot in each region they would be:
- Ilocos Norte ? Pagudpud the Boracay of the north - Ilocos Sur ? Vigan City - La Union ? The surf beaches - Pangasinan ? Hundred Islands
As far as how many tourists are visiting the region, I could only find data up to 2007, where 348,698 people visited the Region of which 41,000 were foreign tourists.
Let me know if you have any more specific questions.