It is partly masked by scaffolding and a boarded-up entrance but this was once a place where the well-heeled of the city flocked, sipping their espressos before a touch of shopping or a film at the cinema. Now, though, Westgate and Riverside park will forever be synonymous with the worst attacks Nairobi had seen in 15 years.
Almost 70 people were killed when gunmen began their rampage on 21 September 2013 while 21 so far confirmed dead during the DusitD2 attack.
They swept through the mall,hotel, holding some hostage and executing others.
Tales of pure horror emerged from the four-day siege. The militant Islamist group al-Shabab said it was behind the attack, in retaliation it said for the involvement of the Kenyan army against it in Somalia.
There are 22,000 African Union troops in Somalia
The Jihadists, a cell of al-Qaeda, are secretive, reluctant to talk.
But now the Kenya Today has had access to a Kenyan man who claims to be an active fighter with al-Shabab since 2007.
He says that his affiliation was for financial – rather than ideological – reasons.
“It was all about the money,” he says. “I was jobless. And then when al-Shabab came with that huge money and they’re giving you that for free, you just have to join them.
“Most of these youths in Kenya, they’re joining al-Shabab not because of jihad or Islam, it’s because of that money. What do you expect us to do? We have to go to al-Shabab to find something to eat tomorrow.”
It was not the first time that countries were targeted for their involvement in the Somali conflict.
Four ethnic Somalis have been accused of aiding the Westgate gunmen
In 2010, 74 people watching a World Cup match on television in Uganda were killed in an al-Shabab attack.
Uganda, Kenya and Ethiopia have joined troops from the Somali government and African Union to drive back the militants from their strongholds. And they have scored key successes, pushing al-Shabab out of cities like Kismayo into the largely rural south.
Beyond the economic factor, the alleged fighter told us revenge for the onslaught in Somalia was an incentive for the attacks but says he feels remorse that the wrong people are often caught in the middle.
“I regret it a lot, because if it wasn’t for money, I would never have gone to Somalia,” he says.
“Kenyan soldiers, Ugandan soldiers, they’re killing people in Somalia. We are hitting back but for me, I feel bad because the innocent ones… Are caught in the crossfire. It’s said in the Koran if you fight jihad, you’ll go to heaven. For me it’s not a jihad, it’s like a retaliation.”
The Kenyan authorities originally claimed 10 to 15 attackers were involved in Westgate but later revised the estimate down to four.
It is alleged that the Kenyan authorities failed to respond to prior warnings of a terror attack
They said all had probably died in the siege. That was backed up by a recent report by the FBI, but runs counter to other intelligence assessments and an investigation by the New York Police Department, which found that the gunmen may have escaped by posing as victims.
As the alleged al-Shabab operative says, the group is well-schooled in such tactics: “You have to know how to use AKs, to get out of trouble, how you can disappear through a crowd.
“So after the training, our next move was to come back to Kenya to settle and then wait for orders. They come from Somalia because you don’t use telephones because they’re traced everywhere. So they send somebody. You get the weapons there.”
There was heavy criticism of the Kenyan government in the wake of the Westgate attacks. Poor co-ordination led to a slow, inefficient response.
Poverty in Kenya has been blamed for some people joining al-Shabab
Ill-trained troops were alleged to have looted shops during the mayhem that ensued.
But, most seriously, the authorities stand accused of failing to respond to prior warnings.
“I have seen intelligence reports that indicate clearly the chronology of the events up to the day of the attack,” says security analyst George Musamali.
“We have credible information that the top government officials in charge of security in this country were given copies of those briefs by Mossad, by the CIA. So I think we hold the government accountable for what happened.”
We played him the recording of the alleged al-Shabab fighter.
“This is very dangerous for Kenya,” he says.
“If youths like this go to Somalia and then return and don’t find something profitable, they might turn their guns on their fellow citizens. This calls for action on the side of the government and the intelligence services to infiltrate these groups and see exactly who is responsible for this radicalisation.”
The fallout from Somalia’s conflict has gripped this region.
A US missile strike earlier in the week was said to have killed a senior al-Shabab leader; nobody knows how the group will fight back next.
But for the alleged operative, his stated plan is clear – and chilling: to become a suicide bomber.
“That vest…you have to know how to build it, you have to know where the trigger is, everything,” he says.
“You know it yourself, because you’re the one who’s wearing the vest. So you have to be careful. God willing I will make it there, if it’s God’s wishes.”