"If you're hiking in the countryside and you see a small lovely path, don't take it, it leads to a dump. Almost every village has one."
Another added that India was "spectacularly bad on this front".
"At one point I asked our tour guide if he knew the location of a trash can and he responded with "I'll take care of that," and threw an empty water bottle over the wall into someone's front yard - 20m from a Unesco heritage site."
Others were surprised to see the number of homeless people in some countries, with many tourists particularly surprised how prevalent the issue was in the United States.
'TimberBucket' said he never mentioned this aspect when discussing his trip to Hawaii.
Another user said he was shocked by the homeless population in San Francisco.
"The first thing I saw leaving my hotel was a guy smoking crack on the street at 4 in the afternoon. Not many people seem to know about it outside the US," he said.
The rudeness of locals was also an issue for some people, with Reddit user 'Kaspium' describing struggles with Parisian shopkeepers.
"As a general rule, I enjoyed my visit to Paris, however I did have a couple of times when I'd visit a shop and the workers would just be dicks to me," they said.
"I speak French ok, but I'm a bit slow, and I'd try to talk in French and the shopkeepers would basically laugh in my face/talk about me to each other when I was standing in front of them."
Other unfortunate travellers reported being robbed while overseas, an experience they preferred not to discuss.
'W00gle' said, "In Amsterdam, even the guy who mugged me spoke excellent English."
Another tourist called 'TheScandinadian' had a similar experience in Jerusalem.
"My parents will never know that I got robbed in Jerusalem. I still love the city but I was definitely on my guard for the rest of the visit. I just don't want them to think less of me."
Sex tourism in Eastern European and Asian countries also shocked many tourists, with 'afellowinfidel' reporting that they were offered "offered underage sex in SE Asia. Way underage".
"It's depressingly common, and many North American and European paedophiles come here for that reason."
Sadly, a female tourist wrote about being traumatised by a sexual assault while volunteering in Peru.
'Selfishevents' said, "I was raped by my taxi driver who knew I was solely in that country to volunteer in the hospitals.
"Cops treated me like s*** and told me the bruises on my neck were love marks, that if I tested positive for any drugs I would be charged because surely I put the drugs in my system knowingly, and that I was just a stupid American who was embarrassed by her fling.
"I just tell people that there was a mix up at the airport [which] is why I came back early. And just talk about the poverty and stuff."
One man had a near-death experience in China and had kept it secret from even his closest family.
His child 'Hellknightx' said: "When my father came back from a business trip in China, he had a broken leg. He told us that he had slipped on some stairs.
"It was only many years later that I found out the Chinese military police had thrown him off a bridge and left him for dead.
"He was part of an arbitration team that had been brought in on a legal case against the Government for negligence. I don't know why he kept it secret from us for so long, but it certainly changed the way I saw China."
- nzherald.co.nz
