Stepping inside stirred a further eddy of dust from the crumbling concrete.
At first, it seemed like an empty film set. But we walked on, among the first journalists allowed in since the end of one of the most fearsome sieges of modern times, the few hundred residents who have not fled peered out from their broken walls.
A handful of black-clad women clustered around an outpost of the Red Crescent. A few more gathered around a man who had been allowed by the army to bring in a small selection of vegetables.
Children pointed excitedly to the ruins, their new playground, running in and out of the piles of detritus.
Few people were prepared to talk, but one man was upset enough on learning he was talking to a Briton to damn the perfidy of David Cameron, who had seemed to want to help but had “done nothing”.
“He is a liar, a liar,” he said. “It was just talk, talk, talk. Nobody helped us. The whole world was against us.”
Another man described how he had been held in prison for 50 days – though not long enough to avoid the savagery of February’s bombardment that finally drove the Free Syrian Army’s Farouq Battalion from the suburb. It was a humiliating retreat which may have marked the turning point of this war.
“Every day for thirty days the shells came. They started at six in the morning and ended at eight at night. In between, there was not a minute’s peace.”
Ask where the FSA went, and there is a nervous silence. Some things still can’t be discussed. “We lived here, they killed us, and they will kill us,” said one resident, succinctly. The army SUVs and pickup trucks come in threes, driving without stopping down the centre of the road.
But it is no secret where the “armed groups” went. Many went to Khaldiyah, which touches on the city centre and which, though heavily shelled, seems a tougher nut to crack.
Walk up from the clock tower in the central square, between the governor’s offices and the Lord Suites Hotel – “spotlessly clean and modern” according to the Lonely Planet guide, a comic thought now – and soon the bullets are cracking. From a side street comes the thud of a rocket-propelled grenade.
It is not clear why: there is no advance on either side, and regime officials may be right in claiming some of the firing is for show, to herald the monitors’ arrival.
The heaviest shooting, though, is at night, long after the monitors have retreated to their hotel.
An army major reckons there are 4,000 fighters holed up in the suburb.
That, too, contradicts the official line that the FSA is nothing more than a handful of criminals, bolstered by foreign fighters and jihadists.
But then the official line is flexible, and perhaps has to be now the monitors are here to see for themselves. The government is now prepared to admit it shares in the responsibility for the disaster that has befallen a city where now smashed open-air cafés and rooftop restaurants speak of a more relaxed past.
The governor of Homs, Ghassan Abdul-Al, looked embarrassed as he claimed the army’s treatment of Baba Amr was proportionate to the rebels’ use of rocket-propelled grenades, mortars and small arms.
But he was only appointed a year ago, after his predecessor was sacked because of his initial response to the protests, and he was prepared to go beyond the standard formula that “some mistakes were made”.
He hoped things might have been different if he had been in charge. “I think I might have been less aggressive,” he said. “Because we see – and as you find – there is a big reason for this uprising. We did not serve the people, not as they should be.”
For Syria to serve the people of Homs now seems almost impossible. Mr Abdul-Al said there were plans to redevelop Baba Amr – the reason, he said, pictures of a brieze-block wall along one side of the suburb have circulated the internet. It is not a “New Berlin Wall”, he said, but merely a replacement for a protective barrier by the railway line.
Baba Amr certainly looks like a place that needs to be levelled. But before anything new can rise from the ashes, its people must be reconciled to those who reduced it to this state. That task lies beyond the building of walls.