Japan’s Southwest Islands, or Nansei-shotō, are the other Japan: a chain of semitropical islands that feel more like Hawaii or Southeast Asia than the main islands of Japan. Stretching from Kyūshū in the north to within sight of Taiwan in the south, these coral-fringed islands are sure to be a revelation to those who make the journey.

First and foremost, the islands are a nature lover's paradise: starting with the islands of Kagoshima-ken in the north, you will find lush primeval forests hidden among the craggy peaks of Yakushima. Heading south, the first stop is Okinawa-hontō, the bustling main island of Japan's southernmost prefecture, Okinawa-ken.

While the main island is great, the offshore islands are even better, including the spectacular Kerama-shotō, a group of tiny gems with white sand beaches and crystal-clear waters. And, finally, there is brilliant Yaeyama-shotō, featuring coral reefs, subtropical jungles and extensive mangrove swamps. Of course, spectacular nature is only the half of it: the southern islands also possess a fascinating and peculiarly different culture to the mainland.

Designated a UNESCO World Heritage Site in 1993, Yakushima is one of the most rewarding of the Southwest Islands. The craggy mountain peaks of the interior are home to the world-famous yaku-sugi, ancient cedar trees that are said to have been the inspiration for some of the scenes in Miyazaki Hayao's animation classic Princess Mononoke. Hiking among the high peaks and mossy forests is the main activity on Yakushima, but the island is also home to some excellent coastal onsen (hot springs) and a few sandy beaches.

If you have had enough of the crowds and resorts of Okinawa-hontō, hop on a ferry to one of the nearby islands, a world away from the hustle and bustle. These islands are among the most attractive in the entire Southwest Islands, with stunning beaches. The three main islands of Kerama-shotō lie a mere 30km offshore from Naha and they are an easy visit as a day trip. However, it is recommended you stay few days in a minshuku (Japanese-style bed-and-breakfast) on one of the islands to really savour the experience.

A mere 2km in diameter, tiny Aka-jima makes up in beauty what it lacks in size. With some pleasant beaches and an extremely peaceful atmosphere, it is easy to get stuck here for several days. There is also some decent snorkelling and diving nearby. There are beaches on every side of the island, but for sheer postcard-perfect beauty, it is hard to beat the 1km stretch of white sand on the northeast coast known as Nishibama Beach.

A stone's throw from Aka-jima, Zamami-jima is slightly more developed, but also has nice beaches and a few rocky vistas. From its offshore islands, there is great diving and snorkelling in the surrounding waters. Furuzamami Beach, approximately 1km southeast from the port (over the hill), is a stunning 700m stretch of white sand that is fronted by clear, shallow water and a bit of coral, and is well developed for day-trippers; you can also rent snorkelling gear here (¥1,000).

If you fancy a little solitude, you will find picturesque empty beaches in several of the coves on the other sides of the island. Better beaches, however, are on Gahijima and Agenashiku-jima, which are located about a kilometre south of the port. Fringed with delightful white-sand beaches, they are perfect for a half-day Robinson Crusoe experience.

Although it is just 20km west of Ishigaki-jima, Iriomote-jima could easily qualify as Japan's last frontier. Dense jungles and mangrove forest blanket more than 90% of the island, and it is fringed by some of the most beautiful coral reefs in all Japan. If you are super lucky, you may even spot one of the island's elusive yamaneko, a nocturnal and rarely seen wildcat.

Needless to say, Iriomote-jima is the perfect destination for outdoor enthusiasts. Several rivers penetrate far into the lush interior of the island and these can be explored by riverboat or kayak. Add to the mix sun-drenched beaches and spectacular diving and snorkelling, and it is easy to see why nature-loving Iriomote-jima, and indeed many of the Southwest Islands, are becoming a popular destination in Japan.

The article 'The lost islands of Japan' was published in partnership with Lonely Planet.