The most interesting of Kota Bharu’s many museums is perhaps the Istana Jahar, housed in a beautiful teak structure built in 1855 by Sultan Muhammad II of Kelantan for his grandson. This is a museum of royal customs, including the rituals involved in marriage, pregnancy and childbirth. To the side of Istana Jahar, the Royal Palace boasts an impressive gateway through which the public are not permitted to pass.

Kota Bharu is served by Wakaf Bharu station, just across the Kelantan River from the centre of the city. On the platform, a mother studies her phone while four children play, two old men sit at a table chatting and small birds hop between the tracks in search of grubs. A mynah bird eyes my biscuits hopefully but flies off when, with a blast of its horn, the 2.19pm to Gua Musang rumbles into the station.

The engine is a tatty old diesel and many of the windows in its three carriages are cracked, but the air conditioning works. I find a seat next to a relatively clear window and make myself comfortable.

It is a six-hour journey to Gua Musang but most passengers make much shorter hops, from towns to kampongs, or villages, and places that seem to be little more than a short raised platform with a nameplate.

Many passengers are dressed in sarongs, the women sporting colourful headscarves and bags of vegetables; the men, some with farming implements, taking turns smoking by the open doors at the ends of the car­riage. Students on their way home from school consult their smartphones, share giggles and feverishly type messages to one another. Hawkers walk up and down the train selling snacks, drinks and bags of sweet oranges the size of ping-pong balls.

The train crosses rivers the colour of strong tea and passes palm oil and rubber plantations edged with scrub. It trundles through cuttings that look more like jungle than the jungle itself.

Late in the afternoon, the train comes to a halt in a siding at Dabong. The entire line is single track and trains can pass only at stations, so if one is running late, those travelling in the opposite direction just have to wait. Passengers clamber down from the carriages, apparently used to such delays, and go in search of noodles. By the time we get moving again, the light is fast draining from the sky. It is at least another two hours to Gua Musang.

According to legend, the area around Gua Musang was inhabited by hunters who would make offerings of animals in front of a cave in the limestone karst. One day, during a storm, a bolt of lightning split the karst in two. The hunters, believing the god of the cave was angry, knelt down to pray. As they did so, a pack of civet cats entered the cave, so the hunters readied their bows and arrows, waiting for their quarry to leave. But the pack never emerged, so the cave was dubbed “civet cat cave”, or gua musang, the name later being conferred on the settlement that grew along the tracks.

The cave can be reached through the kampong by the old station, about 500 metres north of the new station and town. I start off back down the tracks, two young boys watching my progress with interest.

The kampong sits on a sliver of land between the track and immense karst walls, shaded by mango trees and banana palms. Painted yellow with a blue trim, the old station is boarded up, but the sidings seem to be in use; a blue locomotive at the head of a freight train stands cold and lifeless.

The cave is obscured by vegetation and getting to it requires a bit of climbing. The boys point the way but my footwear isn’t up to the job. Any civet cats in residence remain undisturbed.

The 2½-hour run from Gua Musang to Kuala Lipis is the most scenic stretch of the line. The forest comes close to the railway on the east side while towering karst peaks crowned with jungle stud the view to the west. In karst-sheltered villages, children stop playing to watch and wave as the train passes. In some places, palm oil plantations give the landscape a prickly texture as far as the eye can see.

Outside the station, on Jalan Besar, Chinese-style shophouses in a colourful row each bear their date of construction. Some sell the instruments of modern life, such as mobile phones, while the stock in others looks like it hasn’t changed in decades. At the open-sided Hotel Central, built in 1921, friendly locals sit and chat over lunch, coffee and banana fritters.

Ambling along its sleepy streets, it is difficult to believe that, from 1898 to 1955, Kuala Lupis was the capital of Pahang state. At the north end of Jalan Besar, the Masjid Negeri Madrasatul Firdaus is the former state mosque, a wooden structure built in 1888 with funds provided by a Yemeni merchant. Down the hill, on Jalan Jelai, brave business owners keep a wary eye on the river. To the casual observer, the Jelai might seem a safe distance away, but the waters can rise quickly and floods are frequent.

The attractive red residence of the town’s first colonial administrator, Hugh Clifford, is perched on a knoll overlooking the town. It is now a hotel and Clifford’s ghost is said to prowl the corridors at night. Another allegedly haunted colonial relic is the District Administration Building. Opened in 1919 and painted the same deep red, the large, stately building now houses the local government and the district court.

The Pahang Club occupies the oldest building in town. The black-and-white timber structure, built in 1867, was the first administrative building and Clifford’s residence until his own was completed. It became a club, and the centre of Lipis society, in 1926. Although the building looks a little forlorn and unloved, it is not difficult to picture rubbers of bridge on the verandah and starched waiters delivering G&Ts as the sun sets.

Two trains run in each direction each day on most of the Jungle Line, but from here to Gemas there is only one and, as it runs at night, there is nothing to see. So I end my journey at Kuala Lipis, a colonial stiff upper lip against the rainforest.

Modern buildings may be fortify­ing the edges of town, but an emperor cicada, the largest type in the world, buzzes hopelessly around the lamp at the entrance to my hotel on the final evening of my trip down the Golden Blowpipe, a reminder the jungle is never far away.