Here is a guide to Tonga that I found on Boots n’ All.com.
Where is it?: Oceania, archipelago in the South Pacific Ocean, about two-thirds of the way from Hawaii to New Zealand
Why do people go here?: Tonga is one of the more active pacific islands, and people know it. Spend your days hiking, diving, partying, relaxing, just about anything.
What are the main entry points?: Fua’amotu International Airport, outside of Nuku’alofa, is the point for air travelers coming from the major pacific points: Australia, Hawaii, New Zealand and Fiji, as well as some smaller islands.
Currency used: Pa’anga (TOP)
Religion: Christian (Free Wesleyan Church claims over 30,000 adherents)
Ethnic Breakdown: Polynesian, Europeans about 300
Government: Hereditary constitutional monarchy
Languages: Tongan, English
Major Cities: Nuku’alofa
Attractions: Kava, Coral, Hiking
Accommodation: Tonga Hostels
Health Issues: A yellow fever vaccination certificate is required from travellers over 1 year of age coming from infected areas.
When to go: May to October has the best weather, as well as tourists.
Specific Events/Holidays: Independence Day, 4 June (1970)
Getting Around: Rent a car or take a bus on the islands, but expect to pay small fortunes to fly from one to another or take the ferries.