It has been over 400 years since the rise to prominence of the Tokaido – the East Coast highway that linked the new political capital of Edo (present-day Tokyo) with the Imperial seat of Kyoto.

Praises of the old Tokaido have been recorded in prose, poem and picture. The most famous of these is the still-fresh series of wood block prints made by the great artist Hiroshige Ando: the 53 stations of the Tokaido.

Since the rapid modernization of Japan in the mid-19th century, much of the Tokaido scenery has irrevocably changed. But some sites preserve something of the atmosphere of the hey day of the highway and one of these is the town of Kakegawa, in Shizuoka, one of the old post towns on the road where weary travellers can enjoy a meal or a night’s rest. Travellers still stop there, many staying at local hot springs near the town, but they are not likely to be so weary. Many of Kakegawa’s visitors today arrive by the Kodama bullet train from Tokyo, a trip of approximately two hours, instead of five or six days.

Laid out on flat land nestling between ranges of hills, Kakegawa is a typical old Tokaido castle town or jokamachi – thoughtfully and tastefully restored, creating a very good impression of its neatness and compactness. The authentically reconstructed castle keep peers over a tidy arrangement of Edo-style buildings including teahouses, souvenir shops and even a traditionally decorated car park for visitors.

Outer gates of the old castle have also been carefully reconstructed adding to the visual attractions. In short, it is a very pleasant place to visit. There’s little of the uncoordinated architectural mess that characterizes so many other Japanese towns, rendering one almost indistinguishable from another. The old Tokaido runs right through the centre and is now lined with modern shops catering mostly to the locals.

Kakegawa is an important centre of green tea production and there are many specialist shops selling local varieties. Bamboo goods are also produced locally as well as soba noodles, cooking sauces, Wabash seasonings and a few rather good local sakes.

It is also a centre of rose cultivation. Every year four million blooms are grown here in the Yoshioika Rose growing district.

My interest in visiting the town was not just to buy roses, sake or tea but also to verify accounts of the old post town from foreign visitors of the distant past.

For two and a half centuries, few foreigners travelled the Tokaido. However, the Dutch merchants from Nagasaki made regular pilgrimages to Edo to pay respects to the Shogun and towards the end of the Tokugawa period, when Japan was opening up to the outside world, foreign diplomats travelled the Shogun’s highway, often at considerable risk.

One of the observers in a Dutch party of travellers in 1691 was Engelbert Kaempfer, who wrote a detailed account of life in Japan that remained the classic reference work until the 19th century. His passage through Kakegawa was short and dirty.

“As we were passing through this city, a large kettle, where certain fruits were being boiled to obtain a oil, caught fire,” he wrote. His group fled through the smoke and found later that half the 400 houses in the town were destroyed.

Much later, in 1867, “ruffians” from the guard of an Imperial messenger attacked British diplomat Ernest Satow and his party in their Kakegawa lodgings. The unruffled and uninjured Satow reached for his stiff upper lip and demanded an apology, which was duly forthcoming, accompanied much later by the execution of two ringleaders of the failed attempt.

But Kakegawa is home to a mystery, a whodunit? which remains an enigma to this day.

Gijsbert Hemmij, the opperhoofd, or director of the Dutch East India Company’s trading post at Deshima, Nagasaki, became ill, died and was buried in Kakegawa, in June 1798. He was on his way back to Nagasaki after the customary visit to Edo.

Rumours at the time suggested that he had committed suicide, fearing the shogunate’s wrath at their discovery of an alleged Dutch plot to deal illicitly in copper with the Satsuma clan, from present day Kagoshima. There were also claims of illicit trading with Japanese merchants en route to Edo, which had annoyed the government. Yet another version of the rumour is that the Shogun’s law enforcers poisoned Hemmij, for the same reason.

While we know there was a rumour, scant evidence exists to prove that there was a plot – although, as they say – there is usually no smoke without fire.

The Japan trade was not at all good for the Dutch at this period, and a new line of business would have been welcome. The Dutch East India Company was on the brink of bankruptcy and Holland was under French occupation, beset with political strife and approaching war with England.

But a short Dutch diary note on June 7th, the eve of Hemmij’s passing, suggests that the Chief Merchant was not suicidal. “I am not going to die for a long time”, he told a colleague, before passing out, to leave his mortal coil at 11:30 p.m., Friday, June 8th.

So he may not have committed suicide, but had been deliberately poisoned. On the other hand, the poor man may just have been sick. It has been suggested that his symptoms were close to those of typhoid.

If Hemmij were poisoned, the only way to prove it would be to dig up the poor Dutchman and hold an autopsy.

Even after two hundred years that would present problems, the least of which would be dealing with his sturdily built monument. Disinterment is a matter not taken lightly and the present-day Japanese authorities may not want to be associated with an attempt to implicate a former Japanese government in a crime against a foreigner.

The opperhoofd’s well-kept tomb sits prominently in a small graveyard attached to the Ten-nen-ji Temple in Kakegawa, just one street north from and running parallel to the old Tokaido Highway, which the late director’s colleagues took back to Nagasaki after burying their chief.

A three-page pamphlet that is available in the showroom of local products and tourist attractions in the modern and spacious JR railway station, in addition to the tourist information centre in the middle of the town, describes the tomb and includes it in the itinerary of a two-hour walking tour of Kakegawa’s main sights.

An answer to the mystery may well be buried in some dusty archive. Or, more likely, it lies with Hemmij in his lonely roadside tomb. Strange things happened on the Tokaido, and Kakegawa to this day is home to a dark secret.