I like places that make me cry. Does this make me a dark tourist?

Should a holiday make you weep? I don't mean the usual tearjerkers like delays, food poisoning and lost luggage. I'm talking about voyages to the world's epicentres of sorrow.

New York's 9/11 Memorial and Museum is the saddest place I've visited, and I've seen a few. I'm from Scotland, a grief-sodden landscape riddled with ancient battlefields, where ghosts outnumber the living. Culloden, Glencoe, Bannockburn - tragedies undiminished by centuries. If you haven't heard a headless piper playing a lament in a desolate glen, there's no whisky running through your veins.

I've also lived by the Tower of London, that medieval Hotel California where nobody checked out, including Anne Boleyn and Lady Jane Grey, executed at just 16 years old. A melancholy spot, but never lonely thanks to 3 million annual visitors.

Places with troubled pasts pull us. Almost 2.5 million people visited the 9/11 Museum last year. Just over 1.5 million passed through the Pearl Harbor National Memorial in Hawaii, and 1.95 million went to Poland's Auschwitz-Birkenau Memorial and Museum, possibly the most heartbreaking place of all.

At the former Ground Zero, it's hard to know what's most wrenching: recordings capturing victims' farewell calls to loved ones; photographs of people jumping from upper floors; the devastation told in mangled steel beams, entire storeys compressed into molten lumps, trucks crushed like toys. Or simply the long, long list of 2982 souls inscribed on the memorial pools where the towers fell.

The little things undid me. Bent spectacles, shattered wristwatches, charred ID cards. Wallets, handbags, keys, battered Nokia phones. Those commonplace bits and bobs carried to work on the day their owners never came home.

Pearl Harbor is a tomb, with some 900 bodies remaining in the sunken USS Arizona. But the wreck's sombre silhouette and "black tears" of seeping oil sit close to Waikiki's beach playground. Surf, sun and sadness. It can feel disconcerting to step between them.

Same with the 9/11 Museum. Afterwards, at a Yankees game, jazz at Birdland, thrift-shopping in Williamsburg, its shadow lingered. The experience changes you.

I've never wanted to be a dark tourist, like those Instagraming ignoramuses snapping sexy selfies at Chernobyl, or the wandering nuisances with an underdeveloped prefrontal cortex for a compass, making headlines and diplomatic incidents on their misadventures in the world's finest failed states.

They and those gormless gawkers at serial killer sites should be banned from travelling further than their own bedroom. Or sent to the Tower of London to star in super-accurate historical re-enactments. I'll supply the axe.

My number one travel rule: go where you're welcome. Destinations are like friends; some are your good times gang, there for the daiquiris, beach raves and spa days. Others call for closer bonding. They invite you to bear witness to their struggles. And in the spirit of connection, empathy and respect, you should. Think of it as deep tourism, not dark tourism.

At Cape Town's Robben Island prison, where Nelson Mandela was held for 18 years along with thousands more political prisoners, ex-inmates lead tours through their former hell. Why do it, I asked the dignified man showing us his old cell. "We want this to be a place for reconciliation," he said. "For forgiveness."

I found similar optimism in Halifax, a Nova Scotia port struck by two of history's worst maritime disasters. In 1912, all Titanic's recovered bodies were taken there and 150 remain. Just five years later, a horrific harbour explosion killed more than 1900 people, reducing the city to ruins.