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 TaiDong's FuGang harbor to Green Island before heading to Orchid Island. Tickets are NT$920 round trip. 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 TaiDong's train station are NT$350 each way.
The second option is to fly. Daily Air flies three times daily from TaiDong Airport to Green Island's small airport. Tickets are NT$980 one way for adults and NT$460 for children. The flights last 15-20 minutes.
Unless pressed for money, it is suggested that the flight be taken. The ferry makes many people sick.
Before you go, make sure to bring enough cash for the entirety of your visit. Although the island does have two ATMs (that only accept domestic cards), the machines could run out of money and leave you stranded as only the larger hotels on the island accept credit cards.
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.
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.
Besides one of only 3 saltwater hot springs in the world , Green Island has some decent snorkeling and scuba. 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.
Not all of the dive shops adhere to high safety standards so if you are inexperienced diver, caution is advised. Green Island Adventures Dive Center  - 1.5 KM North of the hot springs with Ocean Views and 2 hostels can be recommended - Run by English speaking foreigners - they have the only scuba shop on the island too where you can buy spare parts and scuba equipment and also sell western meats, wines etc. for DIY BBQ's on the premises with ocean views. Great diving is to be had on the Eastern side of the island too - the "wild" side and these guys know their stuff there! but they also dive all the other spots too and enjoy taking divers to the famous Big Mushroom coral. Bikes and scooters and snorkel gear can be rented from them too at very reasonable prices.
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.
Snorkeling can be done for as cheap as NT$300 for an hour or so if you ask around.
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. Here is a link to some eateries with English menu's 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.