MELANIE Olivero can't forget her visit to Ground Zero in New York last year, at the 9/11 Memorial which now stands at the site where 2,800 people perished in the terror attacks of Sept 11, 2001. The 38-year-old television presenter spent some time contemplating the tragedy at the site, which now features man-made waterfalls flowing into two large reflecting pools.
"The guide I spoke with shared some grisly information like how human bones were found on the roofs of surrounding office and tenement buildings years after the attacks. I felt at peace, yet incredibly sad while walking around," recalls Ms Oliveiro, who has also been to Dachau, a former concentration camp in Germany.
She is just one of millions of tourists who have visited concentration camps, battlefields and other places associated with death and tragedy. These include the former concentration camp Auschwitz, the killing fields of Cambodia and Chernobyl - the scene of a catastrophic nuclear accident in 1986. More recently, a group of intellectuals was reported to have proposed turning the edge of the exclusion zone around the Fukushima nuclear reactor into a community cum tourist attraction - apparently to provide employment for local residents.
Enter the latest travel phenomenon known as dark tourism - a term coined by Professor John Lennon of the Moffat Centre for Travel and Tourism Business Development in Glasgow. Or, as more sceptical observers put it, "milking the macabre".
Philip Stone, executive director of the Institute for Dark Tourism Research, at the University of Central Lancashire, wrote in an academic paper this year that dark tourism reflects "not simply an elementary fascination with death but a powerful lens though which contemporary life and death may be witnessed and relationships with broader society and culture discerned".
Whatever the motivations of travellers, there is little doubt that the market for dark tourism is a big one. For example, in 2012, 1.43 million people visited Auschwitz, a record figure for the UNESCO (United Nations Educational, Scientific and Cultural Organization) Heritage Site. The 9/11 Memorial, which opened in September 2011, drew its millionth visitor by the end of the year. And bus tours of areas in New Orleans that were devastated by Hurricane Katrina in 2005 have also proved to be enduringly popular.
For example, Gray Line, a tour agency in New Orleans, promises an "eyewitness account" of the 2005 disaster that killed almost 2,000 people. The tour takes in a levee that was breached by flood waters, while throwing in a history lesson of the city and an environmental message on America's coastal wetlands.
In Singapore, travel agencies say they do not see a great demand for dark tourism, but there are some packages specifically tailored to those who want to visit such sites.
Trafalgar Tours organises a tour of European battlefields from the two world wars, which includes the sites of the D-Day landings in Normandy. Next year, it will also offer a chance to take part in a special memorial service on the centenary of the Gallipoli Campaign in World War I. It will be held at Anzac Cove, where many Australian troops lost their lives. These tours start from just under US$3,000.
Over at CTC Travel, the agency's itineraries also cover destinations such as the Cu Chi tunnels of Vietnam, which were used by the Viet Cong during the Vietnam War, and the Hiroshima Peace Memorial Park, which commemorates the estimated 140,000 people who died when an atomic bomb was dropped by the Allies in 1945. CTC's Travel Private Collection, which caters for higher end customised tours, can cost up to $6,888 per person.
Country Holidays, which specialises in private luxury tours, currently covers Auschwitz and the killing fields of Cambodia. A nine-day tour of Poland, which takes in Auschwitz, costs $5,550 per person on a twin sharing basis.
President of the Regional Travel Corporation, and regional director for Trafalgar, Nicholas Lim is a self-professed war history buff who has been to places such as Dresden in Germany, which was firebombed by Allied bombers in 1945, and the killing fields of Cambodia. He is planning a trip to the European battlefields from both world wars next year.
Mr Lim, 39, remembers the feelings of sadness that he felt in Dresden: "But it was also remarkable to see how the city recovered." He is looking forward to his European trip next year: "It excites me to visit those areas where events which had such a profound impact on modern history took place. Without the D-Day landings and the sacrifice of the thousands of lives over those critical days, the world wouldn't be what it is today."
Other Singaporean travellers say that while they don't go out of their way to visit dark tourism sites, they are drawn by their history. While on a tour of Eastern Europe in April with friends, masters student Gwee Cai Lin, 28, visited Sarajevo, which came under siege during the Yugoslav civil war of the early 1990s. Her hotel was located near the Markale market, where hundreds of civilians were killed in separate mortar shellings. She also visited sites such as a memorial to the children killed during the siege.
Ms Gwee, who also enjoys reading the biographies of individuals who have suffered under oppressive regimes, says: "It was an educational trip, but it was really difficult to comprehend how they could do such things to their own people. There were even Serbian troops shooting at citizens in Sniper Alley, regardless of who they were."
Rather than imply a sense of exploitative voyeurism, Ms Oliveiro says that visiting the likes of Ground Zero somehow "connects you to humanity". She adds: "It's educational in a sense that, if these places touch the inner core of what makes you human, it makes you a more compassionate person."
Bank executive YM Ng has visited Aushcwitz and Hiroshima and agrees that dark tourism has educational value: "It's history. There is nothing to hide, and even children should be exposed to it. It makes people value peace more.
She adds: "You can hear about these places and see them in movies, but it's different when you are personally there and seeing the artifacts, not like the real thing. You feel like you want to pass on these lessons to the people around you."