Wai'ao Beach (aka Gangao Beach 港澳沙灘, or Wai'ao Ocean Recreation Area 外澳海水浴場) in Toucheng township of Yilan County is one of the most popular surfing destinations in Taiwan. It features a long flat sandy beach and constant waves. It is also a special beach in Taiwan because you have a constant view of another island in the distance, Turtle Island. It is definitely a great beach worth visiting.

Background:
The name Wai'ao Beach comes from "Wai (meaning outside)" of the "Ao (meaning harbor),"  because the beach is just past Wushi Harbor. 
The beach has constant waves and many surf shops and showers nearby. 
The beach is usually kept pretty clean and there are umbrellas that you can rent. 
The sand is a darker color which means it can get hot in the sun.
Due to the convenient transportation to the beach, it has become one of the most popular beach destinations in northern Taiwan.

Hours:
24/7

Price:
Free:

How to get there:
By Car: Take national highway 5 east to Yilan and then turn north to Toucheng. There is free parking near the community development center (頭城鎮港口社區發展協會), and the beach is just a short walk from there. 
By Train: Take the TRA to Wai'ao train station. It's about an hour ride from Taipei. From Wai'ao station, the beach is literally just a few steps away. 

Map:
See below:

The Fulong-Coaling-Sandiao Cape- bike route is one of the most biker friendly routes in Taiwan, the roughly 2 hour loop is something that the whole family can enjoy. It includes a 2KM ride through the Old Coaling Railroad Tunnel, as well as a ride along the Sandiao Cape coast on an enclosed bike path, where one can enjoy great views of the ocean, Turtle Island, wavy geological features on the coastline, and historical stone villages along the way. This bike route is highly recommended for people of all ages. 

Background:
The area around Fulong was originally inhabited by the Basay indigenous tribe who has a village and hunting grounds there.
In 1626, the Spanish landed near Fulong and renamed the location Santiago (transliterated from Taiwanese as Sandiao 三貂, as in Sandiao Cape). After the Qing colonized Taiwan, many Fujianese fisherman relocated to the area and began to build the iconic stone houses you can see today.
The Old Caoling Tunnel was ​built in 1924 during the Japanese occupation of Taiwan, and is 2,167 meters long. At the time it was built, it was the longest tunnel in Taiwan.
The tunnel took 3 years to build due to delays from Malaria, remoteness of the location, and digging accidents killing 11 people and injuring over 300. 
The tunnel was only one lane wide, too narrow for electric trains, and so was decommissioned in 1985 and lay waste for 22 years.
The tunnel was reopened when the Coaling Bicycle Loop was created in 2007, using the old Caoling Tunnel as its main looping point. 

Also, along the northeast coast are some old fishing villages that have been around since the Qing Dynasty, including traditional stone houses. One of these historical villages called Magang (馬崗) is in threat of destruction to make way for a resort. however as Li Yongping out it "The thing that attracts modern travelers most is not 5 star hotels, but history and culture!" Save the Magang Stone Houses!
Besides these historical sites, there is amazing scenery along the bike ride, such as views of Turtle Island and long flat sections of layered rock (see below to know what I am talking about). 

Price:
Bicycle Rental: 100-500 NT depending on the bike
Electric Bicycle Rental: 300-400 NT

Riding Time: 
The whole bike route is about 20 KM and takes 1-2 hours to complete.
We were going really slow with many pit stops and it took us 2 hours. 

Hours:
The Old Caoling Tunnel is open from 8:30 AM - 5:00 PM.
It is okay to walk through the tunnel on weekdays, but on weekends only bike traffic is allowed for safety reasons. 

When to go:
May to October when the weather is nice and the water is warm.
Winter on the northeast coast is cold and windy. 

How to get there:
By Train: Take the TRA train to Fulong Station. Walk straight from the station and you will see tons of bike rental shops. 
By Car/Scooter: Take provincial highway 2 from Qidu in Keelung through the mountains past Shifen and Shuangxi until you reach Gongliao on the coast. The beach is right in front of the train station, and there is free parking in front of Dongxing Temple. From there you can walk to the train station where there are bike rentals everywhere. 

Map:
Please see below:

Guishan Island (literally Turtle Mountain Island) is a turtle shaped island off the coast of Yilan in Eastern Taiwan. Once inhabited by fisherman, it is now a coast guard base, but is open for day tours. The island tour includes beautiful sea cliffs, hiking, a lake, abandoned village, military tunnels,  and whale watching just offshore. 

Background:
Turtle Island has been inhabited since at least the Qing Dyansty. When the ROC took over Taiwan, the island had one elementary school and no hospital. Many people relied simply on religion to cure their sicknesses. During typhoons, the dock would sometimes be destroyed, leaving the island without food for days or weeks. Also, there was way more men on the island than women, and it was hard to convince prospective wives from Taiwan to go live an such a remote island with harsh conditions. As a result, the government relocated everyone living on Turtle Island to the main island of Taiwan in Toucheng township of Yilan in 1977. The people could have chose to stay, but they went without protest. The ROC then made the island into a restricted military base. In 2000, the Island was opened for tourism, the military aspects of the island were phased down, and it was made into an ecological reserve. Now the island allows for Tourists to come during the day, but no one is allowed to stay overnight.

How to get there:
The only way to get there is by boat from Wushih Harbor in Yilan. 
To get to Wushih Harbor from Taipei, you can take the TRA train to Toucheng station, and then take a taxi from there. Otherwise you can drive on National Highway 5 to Toucheng; there is free parking at the harbor (drive to the very end of the harbor).
You can purchase a ticket at the harbor or book online in advance via My Taiwan Tour or a similar website.

Price: 
Whale watching on a boat around the island: 800-1000 NT per person.
Once around the island on a boat and 2 hour tour of the island: 800-1000 NT per person.
Whale watching and island tour: 1200+ NT
Island tour including hiking to the top of the island: 1200+ NT
For more information, look other tour/ferry sties or book a personalized tour with My Taiwan Tour.

Hours: 2-4 hour tours start from 8:00 AM or later and end in the afternoon until about 4:00 PM.

When to go: March-November. These tours are generally closed from December to February due to rough seas and cold weather. 

Map of Guishan Island: