Ah, railways. You either played train as a kid or you know someone who did. Trains have been around since the early 1800’s, transporting people and goods from one place to another in increasingly efficient fashion.

However, there are a few train lines around the world that transport people (and sometimes goods) from one place to another in what many would consider to be 'risky fashion'.

From high bridges to train lines with hundreds of tunnels and bridges, this list of 20 train lines that you should probably think twice before boarding presents you with some of the best (or not-so-great) train rides that you can take if you are a little bit of a thrillseeker.

While you may not think that trains in the modern era can be thrilling, this list proves quite the opposite. If you are not a fan of volcanoes spewing lava or a bridge that crosses storm tossed seas, this list covers trains that do just those things.

This is certainly the most comprehensive and complete list of 20 train rides that are fit for brave tourists.

20 Kuranda Scenic Railway, Australia

Constructed between 1882-1891, the Kuranda Scenic Railway in Australia traverses through dense rainforests, across ravines, and past waterfalls. It has 15 handmade tunnels and 37 bridges, making for quite the harrowing ride. This particular train ride will go from a low point at sea level all the way up to over 1,000 feet throughout the entire ride. While it may not seem like a scary ride, when you are riding along in one of the cars on the Kuranda Scenic Railway, you will quickly become aware that you are at the mercy of something bigger than yourself, whether that is the train, the track, or something else.

19 Argo Gede Train Railroad, Indonesia

The Argo Gede Train Railroad in Indonesia is a popular ride for tourists and connects the route from Bandung to Jakarta. Along the route, travelers are able to view plantations, tiny villages, and mountains. There are some striking contrasts between the tea plantations and villages and the Cikurutug bridge and iron bridge that is terrifying because it has absolutely no guard rails to protect the train as it crosses a wide gorge. The Argo Gede Train Railroad is a spectacular ride for anyone to enjoy, but it will certainly get your heart racing as you cross from the level plains into the hills and gorges.

18 Tren A Las Nubes, Argentina

The Tren a las Nubes of Argentina is said to be the "Train to the Clouds" because of the fact that the train travels so high. The ride starts at the Lerma Valley, before traversing up into Quebrada del Toro and crossing a viaduct over a desert canyon. The Tren a las Nubes is a actually a train line that exists solely for tourists and has no real transportation value. There are 29 bridges, 21 tunnels, and 13 viaducts through the route, and the climb is over two and a half miles in altitude, making it the sixth highest rail line in the world.

17 White Pass And Yukon, Alaska

White Pass and Yukon rail in the United States starts at sea level in Skagway and ends up 3,000 feet higher 20 miles later. That makes for a grade of about four percent! The train ride has such a narrow passage and tight turns that it is required to have tracks that are only three feet apart on a 10-foot-wide bed. There is not any direct connection to another railway, so the White Pass and Yukon stands alone as it crosses several deep gorges on its 20-mile trek through the Alaskan Yukon region. This train ride is certainly not for the faint of heart when it comes to train travel.

16 Georgetown Loop Railroad, Colorado

Running between Georgetown and Silver Plume, Colorado, the Georgetown Loop Railroad is a major tourist attraction for school groups and adults alike. The track is four and a half miles long and ascends about 640 feet. The beautiful ride allows you to take in the mountain scenery, but the track was engineered to make it through the steep valley and includes "horseshoe curves" and up to four percent grades and four bridges. It is amazing that this remnant of an era gone by is still running and operated in such great condition, but it just proves that when something is built right, it can run seemingly forever.

15 “Devil’s Nose,” Ecuador

The “Devil’s Nose” train ride in Ecuador is a 45-minute ride from Alausi to Silambe that takes riders through the mountains on a descent that is almost a vertical kilometer. The ride itself is only about 12 kilometers long, which makes for a very steep ride that has two switchbacks. The train traverses past waterfalls, rivers, gorges, and drops. The location for the “Devil’s Nose” train ride is basically on a mountain with perpendicular walls, which is why the ascents and descents are so steep. This is definitely one of the more intense train rides out there and is not really designed for anyone but those that need to use the train.

14 Chennai-Rameswaram Route, India

The Chennai-Rameswaram Route in India connects Rameswaram to Chennai, which cuts what would be a difficult journey by air or sea down to a 1.4-kilometer trip on a train. However, this train ride is all across open water, and there are no guard rails to keep the train from falling off the track and sinking into the sea. Oh, and this part of the sea is prone to storms, making the journey that much more harrowing. The track crosses the Pamban bridge, which was India's first sea bridge. The Chennai-Rameswaram Route may shave time off your journey, but it will also shave years off your life.

13 Lynton And Lynmouth Cliff Railway, England

The Lynton and Lynmouth Cliff Railway in England is the highest and steepest water powered railway in the world, and it connects Lynton to Lynmouth. The track is 862 feet long and climbs about 500 feet, which means that the climb is nearly vertical up the side of the cliffs. This is not your typical train ride, though, as it is more like a tram ride up the side of a cliff. Your car is designed to level against the side of the track, keeping you nearly horizontal as the track rises up against the cliff face. A very unique and scary ride, to be sure.

12 Cumbres And Toltec Scenic Railroad, New Mexico

The Cumbres and Toltec Scenic Railroad in the United States crosses the highest mountain pass reached by a train in the U.S. The ride starts in Chama and then climbs up at a constant four percent grade to Cumbres, the highest point on the route. From there, the train goes down at 2.5 percent grade through "Tanglefoot Curve." The whole train ride is through the wilderness of New Mexico and crosses several canyons and ridges. You may not think that the Cumbres and Toltec Scenic Railroad will get your heart pounding, but the steep climb up and the high altitude will leave you gasping for air.

11 Bamboo Trains Of Cambodia

The Bamboo Trains of Cambodia were built by the people of Cambodia to replace the destroyed French rail lines. The name comes from the hand cards and bamboo rails that the people use for transportation or tourism across the country. The lines are often warped or broken from years of disrepair, making them difficult to use. The carts travel rather quickly, and few have any sort of braking mechanism. The lightweight cars are often removed to carry them around a heavier load. All of this makes for one wild ride on the Bamboo Trains of Cambodia that really is more of a train track-based transportation system.

10 Thailand Bridge (The Name Says It All...)

The Death Bridge in Thailand travels through some of the most beautiful and breathtaking parts of the country. This scenic ride may not seem like a death-defying train ride, but if you know the history of the Death Bridge, you will likely be heartbroken by what went into the bridge. During its construction, about 100,000 forced laborers and some 16,000 prisoners lost their lives to make the bridge a reality. Just another reminder that in some parts of the world, where these practices are still in use, the beauty of the surrounding area may not be enough to overcome the history of the rail line.

9 Aso Minami Train Line, Japan

The Japanese Aso Minami Train Line may seem like any other train line in the world or in Japan. However, there is a little known fact about the area that the train line travels through. The train actually passes right next to the largest active volcano in Japan, and that volcano could erupt at any moment, destroying the train line. Of course, the landscape is beautiful, in a mountainous region of Japan, but riders of the Aso Minami Train Line oftentimes see lava oozing out of the volcano all over the surrounding area. Not a pleasant thought to push aside easily as you try to enjoy your train ride, if you ask me.

8 Schwyz-Stoos Railway, Switzerland

In Switzerland, there is a train line known as the Schwyz-Stoos Railway, and it just so happens to be the steepest funicular railway in the world. The gradient of the track is in excess of 47 degrees with a maximum gradient of 110%. The Schwyz-Stoos Railway goes up about 740 meters over a 1.7 kilometer track and travels at 10 meters per second, which can be a harrowing speed when you are going up that quickly. However, the Schwyz-Stoos Railway is a very unique train line, with the funicular system that allows it to accomplish these speed and climb rates where other trains would fail.

7 Flamsbana, Norway

The Flamsbana line in Norway has one of the fastest drops in train lines anywhere. It drops down a total of 2,833 feet starting at Mydral, and there are 20 tunnels and a bridge to cross to get to the bottom of the hill. The gradient of 5.5 may not seem like much, but the Flamsbana has been rated one of the scariest train lines in the world because of how quickly it performs the feat of getting from the top to the bottom. However, the line is very safe and almost enjoyable if you are able to sit back and just enjoy the Norwegian scenery.

6 Bernina Express, Switzerland

If you are looking for a very scenic train ride that also seems dangerous, then the Swiss Bernina Express is for you. For the sightseer, there are rivers, rocks, rugged peaks, and glaciers. Yet, that ride is complete with spiral tunnels and dramatic bridges—a total of 196 bridges and 55 tunnels complete the line. The Bernina Express climbs to 7,392 feet at the Bernina Hospiz and then descends into the Poschiavo valley with a steep gradient of up to 70%. So, if you like a beautiful train ride, this is for you. And if you like a dangerous train ride, this is also for you.

5 Outeniqua Choo Tjoe, South Africa

Recently reopened, the Outeniqua Choo Tjoe is the last remaining steam-powered train in South Africa. This particular train line was destroyed 2006 but rebuilt and is now operating once more for a scary ride through the mountains and valleys of South Africa. The ride is a 42-mile trip with views of the Indian Ocean. But when you are chugging across rivers and winding through valleys, you are not going to be able to think about much more than the heavy smoke billowing back as the train tears across the South African landscape in a fashion that has all but gone out of fashion.

4 Glenfinnan Railway Viaduct, Scotland

You may recognize this train line. But if you do not, you will not be faulted. The Scottish Glenfinnan Railway Viaduct is so built nearly 100 feet in the air overlooking Genfinnan Monument and the nearby Loch Shiel. As you ride the train, it moves swiftly around the curves of the century old viaduct, and you will feel the movement around that curve for sure. If that does not send a chill up your spine, then looking out and down from the train to the valley floor below is sure to conjure up childhood fears that you would rather have left untouched.

3 Gokteik Viaduct, Myanmar

When the Gokteik Viaduct in Myanmar was completed, it was the highest bridge in the country and the largest trestle bridge in the world. If you have ever been on a high trestle bridge, you know they can be some of the most terrifying bridges to try and cross without losing your lunch. The Gokteik Viaduct connects a couple of towns in Myanmar (Burma) and serves as a major railway in the region north of Mandalay. However, riding on the train across this bridge is not for those that are afraid of heights, as you can just sense how high up you are, even if you are not looking.

2 The Far North Line, Scotland

If you are afraid of being stranded on a train ride, then you should definitely not take the Far North Line in Scotland. This is located in the Highland area of Scotland and is the northernmost railway in the United Kingdom. To say that the Far North Line is "very rural" is a bit of an understatement, as the line traverses through large expanses of bog and not much else. While in the 21st century there is little chance of the line breaking down and stranding people in the middle of northern Scotland, the possibility still does exist, making this a potentially frightful train ride for anyone with a fear of getting stranded.

1 Ferrocarril Central Antino, Peru

Ferrocarril Central Antino is actually the name of the train operator in Peru that operates the second highest railway in the world. The Trans-Andean Railway, which crosses the Andes Mountains in Peru, was designed and constructed between 1871-1876 and is still in service today! Crossing any mountain range is a challenge, but crossing the Andes Mountains of Peru is more of a challenge due to their height and ruggedness. But this train line does just that—successfully transporting hundreds of people leach day across the mountain range, even if a few of them are terrified of the ancient rail way and the steep drops.