On one bank of the Truc Bach lake a small electricity sub-station is plastered with flyers touting a local plumber. Along the road is an aerobics studio where youngsters lazily sip coffee and browse the papers. Thirty yards out across the water - rancid and bobbing with dead fish - is moored a handful of pedal boats shaped like swans.
It was within this unlikely triangle of landmarks - exactly 41 years ago this Sunday - that John McCain crash-landed and, say his captors, began his run for the United States presidency.
For even if the cold, barely conscious US Navy officer did not know it at the time, says Le Van Lua and the other Vietnamese whose lives entwined with Mr McCain's that day, this little spot of Hanoi is undoubtedly where pilot turned politician. If fury had prevailed, it is a transformation that might never have happened, says Mr Lua, 61, a factory worker who was the first on the scene after the crash and swam out to retrieve the battered, politically valuable prize.
He mimes clutching Mr McCain's hair in one hand and a kitchen knife in the other: "I didn't care about the politics, I just saw a man who had killed so many Vietnamese that I longed to kill him. He was injured badly and at the time I was desperate to finish him off. We only stopped because we were told he was more valuable alive. Now I'm glad I did stop: that day was truly the turning point in his life."
Mr Lua's account of that day - along with Vietnamese accounts of the five and a half years that Mr McCain spent as a prisoner of war - differ significantly from the presidential candidate's own record. Mr Lua speaks of quickly getting Mr McCain to the safety of a police station (now the aerobics studio) before any harm was done. Mr McCain writes of mob attacks on his shoulder, ankle and groin with rifle-butt and bayonet.
Where the accounts differ most starkly is in the period of Mr McCain's long incarceration as a PoW - first at the prison known as the Hanoi Hilton, then at The Plantation.
Tran Trong Duyet, the former prison director who now surrounds himself with caged birds in a house in Hai Phong, first met Mr McCain a year after he had been shot down. He recalls a defiant rule-breaker, the patriotic son of an admiral and a fervent believer in the war. What he does not recall, however, is a victim of torture or violence.
"I never tortured or mistreated the PoWs and nor did my staff," says Mr Duyet in contradiction of Mr McCain's account and those of other prisoners. "The Americans were dropping bombs on military and civilian targets - so it's not as if they had important information we needed to extract." Mr Duyet says that he sympathizes with Mr McCain and other PoWs for claiming that they were tortured. "It's up to the Americans to decide whether or not he counts as a hero. He was very brave, very manly, he dared to argue with me and he was very intelligent. But all the talk of being tortured is for the sake of votes."
The McCain campaign refused to comment on the claims yesterday. Mr McCain did eventually sign a confession to his supposed crimes against the Vietnamese people and holds that it was only extracted after weeks of pain inflicted by his tormentors. In a more recent interview Mr McCain explained the signing of the confession as his failure.
Nguyen Tien Tran, another of the directors at the prison, confirms his colleague's story: "We had a clear code of taking care of the injured. We did our best to patch McCain up and he was treated by a good doctor. Why would he say that he was tortured?"
Mr Tran recalls Mr McCain's persistent rule-breaking and even remembers an angry threat to deny him medication if the defiance continued. He also denies that there was any ill treatment of the prisoners, and even remembers sleeping next door to Mr McCain in the hospital to protect him from anyone trying to kill the "crown prince".
Even with differing accounts, those that played a role in his crash, rescue and imprisonment all draw direct lines between themselves and Mr McCain's political ambition.
Back in 1967, what is now the small electricity sub-station by the lake was a sprawling plant that supplied power to much of the North Vietnamese capital.
For the Americans it was a hugely desirable target and what Mr McCain had been ordered to destroy that morning - his 24th bombing mission since the war began.
Flying across the city in a wide sweep, Mr McCain's A4 bomber turned for its final run but was hit by a missile launched 12 miles away. Now a ball of fire, the plane was screaming towards earth as its pilot ejected, broke his arms and knee, and plummeted into the Truc Bach lake.
In a sleepy village two hours outside the capital and surrounded by statues and portraits of Ho Chi Minh, Major Nguyen Lan, 78, traces the day's events on a dog-eared map of wartime Hanoi. "It seems that because of what happened that day I am an important part of his political career," he says quietly.
Mr Lan points to the spot where his Russian-built surface-to-air missile unit was hidden and describes the joy of carefully second-guessing Mr McCain's flight path, giving the launch order at precisely the right moment, and then cheering with delight as the blip disappeared from the radar screen. "I was so angry with America then but time has passed. Shooting down McCain is a happy memory from a terrible war."
Like many Vietnamese, Mr Lan believes Mr McCain has ultimately been a force for good in improving postwar relations between Hanoi and Washington, and holds out hope that, as president, he would continue to strengthen political and economic ties.
"If he does become president it would be good to see him again," says Mr Lan with a chuckle. "We both know that there was a time - that day 41 years ago - when I was more powerful than him."
He offers Mr McCain best wishes for the election but is puzzled at the idea that the candidate could possibly describe himself as a "war hero".
To demonstrate this Mr Lan pulls out an old tin box stuffed with medals he won during a lifetime of military service. Several bear images of burning B52 bombers. The collection includes one of the highest military honors, awarded by "Uncle Ho" himself.
"In Vietnam we are taught to honor the whole unit, rather than the individual but I know it is different in America. Even so, I really don't think that McCain qualifies as a hero. The truth of that day is that he failed and I succeeded. He failed to destroy what he was supposed to bomb and just killed some fish. That is not a hero."
Nguyen Thi Thanh, now a chirpy 81-year-old who is following the US election closely, also briefly had power of life and death over the brash young pilot. As the nurse who first attended to him after he was dragged from the lake, Ms Thanh describes the agonizing choice of whether or not simply to kill him in revenge for the destruction that his bombs had rained on her city.
"As a nurse I had to help him. As a Vietnamese I just wanted to kill him. Everyone around me wanted him dead too but we had to follow the Ho Chi Minh ideology. As I walked home from the nurse station, people were furious - screaming at me for saving his life."
She wonders aloud about what sort of president he would make. "In the end I think that he must have known that what he did was wrong. If he does become president of the US, he must do good things. But everyone has secrets hiding in their minds. I'm sure he's still extremely angry."
As the months of captivity in the Hanoi Hilton and Plantation rolled on, Mr Duyet wanted to examine those attitudes for himself. He describes a growing fascination with Mr McCain and a series of regular discussions the two had.
"I wanted to deal with him. I wanted to talk about the war and to discuss who was right and who was wrong. In the end I don't think either of our opinions changed. Maybe after the war, or as he was leaving, he saw the destruction that had been done and saw he was wrong."
He is clear that he played a role in turning Mr McCain from a pilot into a politician. "If he says it was the war that changed him it must be true, because he spent most of the war with me. I was there to do two jobs in that prison - one was practical, the other political - and I believe I succeeded in both."
Of all the Vietnamese who knew Mr McCain, Nguyen Tien Tran, the director at The Plantation between 1965 and the release of the PoWs in 1973, believes that he has the deepest insights into the man's character.
"He's not [morally] good enough, not enough to call himself a ‘good man' after everything he did, with the bombing and the destruction and the thousands he killed. He has done good things for Vietnam-US relations but none of it is enough for him to call himself a good man. If he makes it as president I want him to come back here and admit that the war was wrong."
Critically, Mr Tran believes that it was during one of their regular conversations that Mr McCain first mooted the idea of becoming a politician.
"I once asked him, ‘What are you going to do when you get home?' I asked him because of his injuries - I could see that he wasn't going to remain a pilot for much longer. He paused, and thought about it, and told me he would become a politician.
"Now he stands on the brink of becoming the world's most powerful man, I want to tell him that I'm like his father. I was the one who gave him a second birth.
"He's come back here ten times but he's never met the people who saved his life. So I can't believe he's a good person."
Life on the inside
"I was hauled into an empty room and kept there for four days. At intervals, the guards returned to administer beatings. One held me while the others pounded away. They cracked several of my ribs and broke a couple of teeth. Weakened by beatings and dysentery, with my right leg again almost useless, I found it impossible to stand.
"On the third night I lay in my blood and waste, so tired and hurt that I could not move. Three guards lifted me to my feet and gave me the worst beating yet. They left me on the floor moaning from the pain in my arm. Despairing of any relief from pain and further torture, I tried to take my life."
Adapted and extracted from Faith of My Fathers, by John McCain (Gibson Square)