The train click-clacks along at a steady rhythm, passing through various shades of green. Lush rice fields morph into dense forests, while rivers glisten in the morning sun.
The verdant, tropical landscape is briefly interrupted by colorful sparks of life in the form of towns and villages, where people are going about their morning routine -- street vendors serving breakfast to commuters, women carrying fresh produce back from the market and kids gathering in their red and white school uniforms.
This is the view from the Argo Wilis Panoramic, a bright and airy carriage on the Argo Wilis train. Running between the cities of Surabaya in East Java and Bandung in West Java, it's one of the most scenic and underrated train journeys in all of Southeast Asia.
For some context, Indonesia is the world's largest archipelago, home to over 17,000 islands. While boats and planes are typically the main way to travel between each island, on Java, trains are by far the best choice.
Stretching 1,064 kilometers from east to west and home to well over half of Indonesia's population -- that's a whopping 275 million people -- it makes sense that the rail network is so extensive and well-used.
Kereta Api Indonesia (KAI) is the country's national rail company. While there are limited train networks on the islands of Sumatra and Sulawesi, the large majority of them are based in Java, linking all the major cities including Jakarta, Bandung, Yogyakarta, Solo and Surabaya.
Most of this network was constructed during the Dutch colonial era, which lasted some 350 years.
Each train has its own name with its own meaning.
"For example, the Argo Wilis is named after a non-active volcano in East Java," explains a railway guard. "There are other trains named after volcanoes too, as well as historic places and Javanese myths and legends."
What's unique about Indonesian trains is that rather than having a single carriage dedicated to a certain "class," each entire train is one of three classes -- economy, executive or business.
Whichever class you're in, they're impeccably clean and comfortable, with reclinable seats, footrests and air-conditioning -- a must in Indonesia's tropical heat. The trains are also incredibly punctual and affordable.
The journey on the Argo Wilis Panoramic between Surabaya and Bandung takes just under 10 hours and costs Rp 1,200,000 ($77) per person for a one-way ticket in the panoramic carriage, and just Rp 680,000 ($43) on the rest of the executive train.
As well as the Argo Wilis Panoramic, there is also the Argo Parahyangan Panoramic and the Pangandaran Panoramic running back and forth between Jakarta and Bandung.
The panoramic car costs a little more than the rest of the train's carriages, but the ticket comes with plenty of perks. Even before boarding, passengers can start their journey in style at the stations' executive lounges, which include complimentary food and drink. On the train, hot drinks, a snack box and a main meal are provided. There's also free Wi-Fi, although, with such incredible views, there shouldn't be much time for scrolling.
Purchasing tickets is easy. Much like the rest of Indonesia, the railways have been quick to embrace technology, particularly in the form of mobile apps. The best way to book is either Traveloka or Tiket.com, two of Indonesia's largest online travel companies. It's also possible to book tickets on the KAI official website, but the site is only in Indonesian and only accepts Indonesian credit cards. Tickets don't need to be printed -- simply scan them from your phone at the station.
For those traveling on the Argo Wilis Panoramic who want to break up the journey, there are several cities along the way well worth spending a few days exploring. (If you want to make stops, you'll need to book your tickets to each of these destinations individually.)
Among the highlights is Yogyakarta, one of Indonesia's most interesting cities, and the only one that still has a monarchy. It's the center of the country's arts and cultural heritage, with creative industries such as silversmithing, shadow puppetry, traditional dance and batik textiles, an ancient art form that dates back over 2,000 years and is thought to have originated in Java.
There's plenty to keep visitors busy, from walking around the Kraton (the royal palace) to shopping for locally-made arts and crafts along the famous Malioboro Street.
Of course, no visit to Yogyakarta can be complete without visiting the UNESCO World Heritage Sites of Borobudur and Prambanan.
Located on the outskirts of the city, Borobudur is the world's largest Buddhist temple, dating back to the 8th century.
Surrounded by forests and mountains, it's one of the most incredible attractions in Asia.
On the opposite side of the city, you'll find Prambanan, Indonesia's largest Hindu temple. It's a huge site, and it's worth visiting the smaller, quieter temples within the area, which are just as fascinating.
For more arts and culture, Solo is an interesting city just an hour and a half by train from Yogyakarta. Historically the center of power in Central Java, it's home to historic buildings, temples, markets and artisan workshops. Keraton Surakarta Hadiningrat, the former royal palace, is worth a visit, as well as the museum, which has a large collection of antiques and artifacts.
Solo is also one of the major centers for batik production. As well as workshops at Laweyan Batik Village, you can also browse for batik goods at Pasar Klewer, a traditional market, while Pasar Triwindu is an antique hunter's dream.
If you happen to have room in the itinerary for a little day trip (always advisable when traveling in Java), the countryside around Solo is beautiful. An hour's drive from the city are the 15th-century temples of Sukuh and Cetho, located on the slopes of Mt Lawu. Be sure to visit the nearby Jumog Waterfall for a refreshing swim to cool off from the intense heat and humidity.
If you're traveling west on the Argo Wilis Panoramic, it's worth exploring Bandung, where the train terminates. Set in the highlands at about 768 meters above sea level, the city enjoys a much cooler climate, making it a nice respite from other cities on the island.
Nature is everywhere you look, from the tree-lined boulevards to the forests and tea plantations that surround the city - there's even a smoking volcano, Tangkuban Parahu, just an hour's drive from the station in the city center.
Sometimes referred to as "the Paris of Java," Bandung has a distinctly European feel thanks to the numerous Dutch colonial and art deco buildings, many of which have been transformed into trendy coffee shops and hip boutiques.
The city is a foodie's dream. From street vendors and food markets to high-end dining, visitors are spoilt for choice.
Whether you're making stops or traveling the whole way through, the Argo Wilis Panoramic is the best way to take in Java's varied, often stunning scenery.
"Trains are probably one of the best things about Java," says one fellow passenger, a British woman in her 60s who is taking the slow route across the island with her husband.
"It's criminal to take a flight and miss out on all of this," she says, waving her hand towards the large window as the train curves around another bend, revealing yet more terraced rice paddies enclosed by breezy palm trees.