The volcano Fujisan is the icon of Japan and something you have to at least see, but even better hike. Its symmetrical cone is easily visible from Tokyo on a clear day and it's only getting more impressive the closer you get. The trek to the summit is fairly easy (though cold) and there are huts and tea houses along the routes that are open in the season (1st July to 27th August). It's probably the most trekked mountain in the world with more than 200,000 trekkers per year, but it only adds to the pilgrim experience to do it in crowds.
The ruins of Nakagusuku Castle (built in the early 15th century) are another of Okinawa's UNESCO enlisted Ryukyu sites. It's perched on a hilltop and the curved lines of the stonewalls follows the natural rocks neatly. But the biggest attraction isn't the location, it's the overgrown state. Like many of the other castle ruins on Okinawa, only the stonewalls stand, but here plants and palm trees have had a chance to grow to give the ruins a wild feel. Cobbled pathways lead to new corners and a walk up on the walls will constantly offer new vantage points of the castle ruins. Nakagusuku certainly has a feel of lost world, which the other more manicured Ryukyu castle sites lack.
Okinawa has several castle ruins, which are united as one UNESCO World Heritage Site. They date back to the Gusuku period (12th-15th century), when Okinawa was ruled by three kingdoms. Nakijin Castle was built in the late 1200s and were the castle for the northern kingdom, Hokuzan. In 1416 the Hokuzan Kingdom was invaded by the middle kingdom, Chuzan, which then went on to unify Okinawa in 1429, as part of the newly established Ryukyu Kingdom.
Today the castle ruin is known for its rebuilt outer stonewalls, which gives a good picture of how big the castle actually has been, but the rest is left to the imagination. It's surrounded by lush forest and with splendid views the northern part of Okinawa and the East China Sea.
This outdoor ancient religious site is a part of the UNESCO World Heritage Site, which also includes other historical sites on Okinawa from the Gusuku period (12th-15th century). It served as a place of worship, religious ceremonies and rituals for the Ryukyuan people (also way after the 15th century), but was later used as a Shinto shrine. The area is a densely forested hillside with an ancient stone path leading to a couple of simple platforms under some cliff overhangs. It's a very tranquil site with plenty of shade.
When the kings of the Ryukyu Kingdom weren't at Shurijo Castle, they spent time here in the royal garden. It was constructed in the 18th century in a blend of Chinese and Japanese landscape styles with ponds and bridges (since Okinawa was trading with both Japan and China at the time). The garden was completely destroyed during WWII, but has since been neatly rebuilt, and is today a part of the UNESCO World Heritage Site, which also includes the Gusuku castles and ruins around Okinawa.
The shady royal garden will come as a much needed break from the fierce sun, if you come during the hot summer months.
Shuri Castle is not a ruin, but a fully reconstructed castle with manicured walls and colourful wooden buildings - even the caretakers are dressed in historic costumes. Shuri was the capital of the Ryukyu Kingdom. The original castle was built in the late 1300s, but wars and fires had it destroyed multiple times over the centuries. The current reconstruction is from 1992 and the new buildings are actually rised above the original ruins to protect them. Parts have been rebuilt in the original style, while others are more museum like.
Many consider Shuri Castle to be the crown jewel of the UNESCO World Heritage Site, which also includes other historical sites on Okinawa from the Gusuku period (12th-15th century).
Zakimi Castle is another castle ruins belonging to Okinawa's UNESCO enlisted Ryukyu sites. It was built in the early 15th century and is nested on a hilltop among pine trees. The neatly restored limestone walls have patches of plants growing on them, but otherwise it's a very manicured site. The interior can even seem a bit dreary with outline of a single building and green grass elsewhere. However, the stonework going into the two arched gates are truly impressive (apparently the first on Okinawa to use a keystone). You can walk on the massively wide walls, which offers splendid views of both the site and the outside area.
The old port town of Melaka (Malacca) has a long and rich history as a sultanate, colonial trading town, and regional powerhouse. Waves of immigrants have arrived through time, adding a piece to Melaka's unique heritage. Today, Melaka still receives hordes of foreigners, this time not from the sea, but in bus coaches armed with cameras and hand fans. The cute well-restored trading houses, the colourful colonial architecture, the temples and the mosques go all too well with the tourists, and the fact that Melaka was granted a UNESCO World Heritage status in 2008 only adds to that. A wonderful spinoff from Melaka's popularity is its famous fleet of bicycle rickshaws, which have been pimped out to the limit that drivers need to push them over any tiny climb due to excessive load of loudspeakers, plastic flowers, parasols... well, anything kitsch - they are super touristic and tacky, but how can you not love them?
One thing that makes Mt. Kinabalu stand out from other mountains is the fact that it is possible to take in its full scale. On a clear day you can splash around in the South Chinese Sea along Borneo's shore and see Mt. Kinabalu's grey dome rise dramatically above the green and lush jungle less than 50 km inland. Today, no skills are required to trek it and the tracks are well marked. It can be done in a very long day, but two days are strongly recommended. This way you can get some rest in one of the huts below the bald granite, before heading for Low's peak, which is the highest point, in total darkness to watch the sunrise light up Borneo.
Big holes, tunnels and cave systems with the biggest known cave chamber (Sarawak Chamber) exist here in Mulu National Park. Some of the caves are show caves with boardwalks and artificial lights on the stalagmites and stalactites, but real caving trips are also possible to arrange with one of the national park's experienced guides. Seeing the Sarawak Chamber (600 m x 415 m x 80 m) is a very difficult and demanding expedition, so don't count on seeing it on your first trip underground. Overground, the jungle and its wildlife can be explored from canopy walks spanning between the tree tops. Don't forget to see the bat exodus at dusk, where millions of bats set out from the caves on their hunt for food. They just keep coming out and draw thick waves in the evening sky. An incredible sight not to be missed.