Why do people visit former concentration camps? Or the site of a terrorist attack? Or former prisons?
None offer the relaxing, lighthearted experience many of us have come to expect on vacation, but all have become accepted tourist destinations -- and such visits are only increasing in popularity.
Now, a team from the UK's University of Central Lancashire is to become the first in the world to study the phenomenon of 'Dark Tourism', hoping to offer insights into how sites such as Auschwitz, Ground Zero or former KGB interrogation centres enjoy such widespread appeal.
Phillip Stone, the director of the new Institute for Dark Tourism Research, told the BBC that he believes visitors are looking for a sense of meaning in places of suffering, which allow time for a sense of empathy with those involved before stepping back into the safety of their own lives.
It's a by-product, he suggests, of a new space in a secular world, where tourists attempt to connect with death and their morals without the traditional framework of religion.
Anecdotal evidence suggests that dark tourism -- academically known as thanatourism -- has been growing in popularity in recent years, although specific figures are hard to come by.
Dr Stone, however, argues that the phenomenon has a long history, suggesting that medieval executions were an early form of dark tourism and the practice has continued to the present day, even as the subject matter evolves.
As part of its work, the institute will examine ethical ways to develop dark tourism, managing sites to allow people to visit and observe without their becoming voyeuristic.