Fiji

Fiji, or the Republic of Fiji, is a South Pacific island situated to the northeast of New Zealand. The country consists of more than three hundred islands, with the two main islands Viti Levu and Vanua Levu accounting for nearly all the country's population. The island, born from volcanic activity, still plays host to a significant level of geothermal action. 

Your options for travelling to Fiji without flying are severly limited. Cargo ships are the easiest way, although they are not quick or cheap. Once you get to Fiji however, the two main islands have extensive bus services serving towns as well as rural areas.