Green Island (Taiwan)
Green Island (綠島; Lǜ Dǎo) is located off the coast of Taitung County.
Several small villages are found around the island, but officially the entire island is considered as Green Island Village.
Mandarin Chinese is spoken by the locals just as on Taiwan, however their accent is heavily influenced by Taiwanese Hokkien. Many people will also codeswitch between the two without realizing, and older people often have a lower level of Mandarin fluency. If you feel in trouble, find the youngest person possible as their Mandarin will be perfect and they most likely have learned some basic English in school.
Two options are available for those heading to Green Island.
The first option is by boat. The ferry heads from Taitung's Fugang Harbor to Green Island before heading to Orchid Island. Tickets are NT$980 round trip normally, but can be obtained for a significant discount from Green Island guesthouse owners and tour operators. The trip lasts about an hour. Motion-sickness bags are plentiful around the ship and many are used when the sea is choppy. Taxis from Taitung's train station are NT$200-350 each way (depending on your negotiation skills).
The second option is to fly. Daily Air flies three times daily from Taitung Airport to Green Island's small airport. Tickets are NT$1130 one way for adults and NT$460 for children. The flights last 15-20 minutes. Free 1-day bike rental at Ludao Airport upon arrival with proof of boarding pass.
Despite the ferry's rather fearsome reputation, the choppiness of the ride depends entirely on the weather-- particularly, wind speed. On calmer days, the Taipei-Taitung train ride is arguably more likely to cause motion sickness than the Taitung-Ludao ferry.
Before you go, make sure to bring enough cash for the entirety of your visit. There is a single ATM machine on the island, at the Post Office (window on the right), across the street from 7-11 (which incidentally does not accept credit cards). The machine does not accept international debit cards, and could run out of money, leaving you stranded.
Scooters can be found lining the roads around the harbor on Green Island. Most guesthouses include a scooter rental in their accommodation packages. There is a single gas station on the island near the port open from 8 AM to 5 PM. After picking up a rental scooter, it is strongly advised to immediately fill up for the day.
Cars are also available for rent for as little as 1500 TWD for a small, old car (as of August 2014). Car rental is in a legal gray area so acceptance of driver's licenses is lax-- some companies may accept a US driver's license, while others will insist on an international driver's license. The rental company may in fact take your license as a deposit, essentially leaving you to drive around without a license.
Besides the scenery, there is an old jail which has been converted into a small museum. Also along some of the paths it is possible to see deer, especially in the summer.
Round the island tour. Star gazing at night.
Green Island is surrounded by coral in almost all directions. However, access is extremely limited due to the geography of the island.
There are three designated sites for snorkeling: Chai Kou (in the north), Shi Lang (in the west), and Da Bai Sha (in the southwest). Each of these sites have a concrete walkway that takes you past *very* sharp coral rock to the drop off. Thick-soled shoes or sandals are absolutely necessary to snorkel these area, even with the concrete walkway. Avoid low tide, as the water level around the walkway will be low, leaving you to walk rather than float past the sharp rocks surrounding the entry.
If you go with a tour group, they will furnish you (in typical Taiwanese style) with life preservers, wetsuits, flippers, and bread with which to feed the fish. Most of this is probably completely unnecessary, although the occasional jellyfish has been known to find its way to Chai Kou (in the north).
Snorkeling outside of the three designated sites is highly discouraged even for experienced snorkelers as the shore generally consists of a few hundred meters of sharp coral rock, continuously pounded by waves that, if not of surfing quality, are certainly large enough to knock you off your balance and cause an encounter with the reef that both you and the coral will regret.
The sites along the north side feature mostly hard corals while the southern sites feature mostly soft corals. The north side is home to many species of nudibranchs and several species of pygmy seahorses. Unfortunately the north cannot be dived in the winter due to the strong winds and waves at that time of year. Beware the current as it is very strong, there are a few places with little current that novice or beginner divers can use however.
Blue Safari Diving Center - in Gongguan village in the North of the island can be recommended, good equipment, reasonable prices and best of all - friendly staff!
One famous attraction underwater is (claimed by the locals) the oldest and largest living coral head in the world. It is about two stories tall about about 4 meters wide. A very beautiful site but it requires a 300 meter round trip swim to visit.
Zhaori Salt Water Hot Springs
Supposedly, Ludao has one of only three salt water hot springs in the world (the other two being in Japan and Italy). The 200 TWD entry fee covers showers, changing facilities, a basket for your belongings, and access to two areas: the "natural springs" and "spa" areas. The natural springs are adjacent to the sea and consist of rock-lined pools with unfiltered seawater at three different temperatures. The spa area is also supplied by the same salt water springs, except that the water has been filtered and sanitized. It consists of a series of hot water pools with jets, showers, and other spa amenities (as well as a super-hot pool where you can boil food). Access to the spa area requires a bathing cap (for both men and women), which can be bought at the shop for 50 TWD.
If you are staying in Nanliao village and are tired of the motorcycles all around you, there is a pleasant walk to get away from the crowds. Just continue the walkway of the esplanade on the left side of the road towards the airport. The path continues between the houses facing the mainroad and the seashore. At the end of the village keep left and you will reach an old graveyard with overgrown tombs. It's a very nice and calm scenery with the airport, the lighthouse and the mountains in the background. If you are lucky you might even get a close-up experience of one of the rare starting/landing airplanes. The path splits at some point but always keep to the left side. While approaching the airport from the left side you can walk down to the seashore and relax for a while. It's not possible to reach the lighthouse from this side because of the airport so it would be necessary to walk at least half of the way back. This walk is good if you are arriving around noon time and looking for a nice afternoon activity.
There are also two hiking paths across the island. Just pick up a flyer at the visitor centers for a map and more details about it.
Cheap bicycles (~150 NTD) can be found next to the harbor. However, they are generally in a bad shape and rusting away. Check carefully before you take a ride! The ride around the island is a 19km trip which can easily be done. As an alternative there are tons of motorcycles and e-bikes available around the harbor.
Many small restaurants can be found on the road between the port and the airport. A local specialty is deer meat from the native deer. Some live deer are attached to ropes to the restaurants themselves.
There is a 7/11 and Family Mart on the island open 24 hours like on Taiwan, however the prices are inflated and stock may run out more easily due to less frequent restocking. Neither have ATM machines. Here is a link to some eateries with English menus on Green Island Taiwan 
Here is a Green Island APP  with maps of Green Island Taiwan and the position of the hospital and some emergency numbers. Please note that sunburn is the most common "injury" here so be sure to protect your skin.
Mondays are typical commute days for residents of Green Island to Taiwan. If you are traveling away on Monday, be sure to reserve ahead.