Pollution, smog, opens feces from human and animal, vermin, and lots of dust and dirt. Pakistan is a country which has not been controlled properly and if you see there is a population explosion, lack of education and discipline.
In Pakistan, it is perfectly okay to throw your garbage on street from your balcony, or to throw half-eaten apple or banana peels from car onto the road. Kids routinely throw candy wrappers, waste papers or chip’s packets on street and are probably never condemned by their parents and the legacy passes on. For the kids’ case, sometimes it is possible though that one neighbor or other might object to kid throwing garbage; such objection is often met with a counter-objection by the kids’ parents, so in essence parents actually encourage kids to litter. It is probably “how dare you say anything to my kid” attitude.
I have seen examples of families being driven in a car and one of the members is sick and is vomiting from the half window down and the car is still moving. The family’s head who is probably driving the car doesn’t give a shit about the sick member of the family and filth he or she is emptying on the car’s door.
Other examples like open urination, spitting everywhere huge mountains of garbage seen at the periphery of cities and smaller gardens of filth at periphery of smaller localities are already covered in other answers.
The fact lies that disciplinary measures should have been brought in by the government (humans are by nature indiscipline until governed by strict laws which can subdue them). Let’s take Singapore, it’s because of the law of the land and the fines and legal implications that repel people to dirty and thus discipline becomes a habit. Same ideology should have been introduced in Pakistan but this country is ruled by politicians with no social service backgrounds across and they are busy Amassing wealth for themselves and therefore forget the reason why they were elected, well there is an irony to this also. Most of the educated class does not vote and very few of this country’s population pay tax so, where the government funds and the money which is available, are used up in corruption. The people who vote are called the vote banks, when it comes to elections, they are given goodies to vote and they happily do so without any sense.
I am already feeling sick as I have finished writing this. So yes in my opinion we are one of the filthiest nations, I guess. This comes from a person who loves his country and is saddened to see my fellow countrymen suffer.