"It was a beautiful starlit night, no wind, and the sea was as calm as a lake," one survivor recounted. But it would not stay that way.

First, survivors remembered a forceful shudder that jolted them forward. Then the frenzied evacuations of women and children began. Those lucky enough to escape the TitanicThe RMS Titanic was the largest ship afloat at the time and it is the deadliest cruise ship disaster in history. witnessed the 50,000 tonne iron ship sinking to the bottom of the ocean.¹

It is now more than 111 years since the RMS Titanic cruise ship crashed into an iceberg and met her tragic fate, but the incident remains notorious. And, along with other infamous disaster zones from ChernobylThe disaster, in 1986, involved a meltdown at a nuclear plant in Ukraine. to FukushimaA prefecture in Japan that was the site of a nuclear powerplant meltdown in 2011. An exclusion zone around the nuclear power plant still exists ten years after the disaster.  to PompeiiA Roman town in Italy. It was buried under ash after a nearby volcano erupted. The ash preserved the town so well that today people can walk through the streets and into some buildings., the site of the accident has become a legendary venue for "dark tourism" fanatics.

Of course, there are certain logistical problems associated with visiting a ship that is currently 4,000 metres underwater. Tours are highly exclusive, costing almost £200,000 per visit, and take place in small submersible vessels that explore the shipwreck. Tripmakers have to sign a waiver accepting that they may die on the trip.

If sounds like the setup to a survival thriller, some point out. But on Sunday evening, the latest vessel to make the trip suddenly disappeared - in real life. On board are five people, including the British billionaire Hamish Harding, and the CEOThe Chief Executive Officer is the highest ranking person in a company. They are responsible for making decisions about the company's future. of the company that runs the tours himself, Stockton Rush.

There is only 96 hours' worth of oxygen on board, which puts a significant time pressure on finding the small submersible. Experts are already losing hope.

For some, it is hard to imagine signing away your life for an eight-hour-long tour around a shipwreck, let alone one that is essentially a graveyard for over 1,500 people. But dark tourism is a growing trade, and one that people are going to extreme lengths to cash in on.

Dark tourism fans eschewTo avoid something on purpose. beaches, busy capitals, resorts and cruises in favour of the grim and macabreGruesome or ghastly.. For some, it is a way to memorialise the less honourable moments in our past; but others say it is pure exploitative spectacle.

Some point out that there is a continuum. Sites like AuschwitzNazi death camp where over a million people lost their lives during WW2. are educational, and serve to situate historically shameful events in a context which can help us to understand their gravity. 

Others merely offer tourists a chance to gawp at devastated cities, people and environments. TurkmenistanA country in Central Asia with a population of 6.3 million. 's "Gates of Hell" gas crater, which resulted from a failed SovietRelating to the Soviet Union, a powerful group of communist republics, the biggest being Russia, that existed from 1922 to 1991. drilling project and has had a colossally harmful environmental effect on the country, is one of its main tourist draws. Some tourists weather radiation risks to visit sites of nuclear disaster like PripyatA city in northern Ukraine that has been abandoned since 1986, due to the Chernobyl nuclear disaster..

We have always gone to great lengths in the name of entertainment. From Rome's ancient blood sports to the brutal public executions of the Middle AgesThe Middle Ages was the period in European history that came between ancient and modern times. It lasted from about 500 to about 1500., it seems that there is something attractive or even thrilling about gore, death and violence.

But dark tourism still splits opinion. Not many people baulk at visiting the catacombsAn underground cemetery, with passages and rooms where bodies were buried in the past. of Paris or the ruins of Pompeii, but many are not comfortable with visiting more recent sites of death like gulagsForced labour camps established by Joseph Stalin in the Soviet Union, housing both small-time criminals and political prisoners..

Its advocatesSomeone who publicly supports or recommends a particular policy. The word originates from the Latin vocare, meaning to call. are adamant that the right way to raise awareness of the dark side of history is through standing in the victims' shoes, in the very same places that they drew their last breath. But many say it feels more like dancing on their graves.

Yes: Dark tourism is no longer about learning respectfully about the darker times in our history. It is about spectacle and taking pleasure in horror. You can see that from the boom of true crime.

No: There are plenty of "dark tourism" sites that acquaint tourists with really important historical events and help them to gain valuable context.

Or... As with everything, there is a spectrum. When dark tourist sites are run by charitable organisations or non-profits, they are likely to have a positive purpose. When they are run by profiteers, inevitably it will be more about spectacle than substance.