By Alex Kirby BBC News Online environment correspondent in Johannesburg

From the outside, the police station in the township of Alexandra looks grim.

Inside, you thread your way along a corridor of iron-barred doors.

Where there's hope we can make things happen

Tony Blair

Then, all of a sudden, you're in an enclosed garden, one to do credit to an English cottage.

Here, hotfoot from the World Summit on Sustainable Development all of 10 minutes' car ride away, the UK prime minister suddenly materialised.

So began Tony Blair's visit to Alex, as it's universally known - probably the nearest he'll come to Africa during his South African stay.

'Change is happening'

It was a chance to meet the station commander and other local people, while the cream of the British media trampled the police officers' carefully tended garden into the ground in their search for vantage points and sound bites.

Some of those meeting Mr Blair were local officers trained by the Metropolitan Police in London.

Tony Blair pledged the summit would deliver results

The Alex police are twinned with their counterparts in the inner London borough of Southwark.

Asked by BBC News Online (carefully not standing on a police plant) what he thought of Alex, Mr Blair replied: "I was here several years ago and it's fascinating to see the change.

"The trouble is that we get frustrated, government leaders as well: we want everything to happen very quickly. But change is happening, and it's on the basis of equality and justice."

British help

Then it was off in a motorcade of 10 Mercedes to look at a housing development and then to the Jukskei river, where gold was first found in South Africa.

Goats graze beside it and a rich aroma of unknown origin is all too evident.

But the river too is improving, we were told, thanks to British money.

The prime minister gazed musingly over the slow-moving water, before dealing with an importunate question about progress back in Sandton.

"The summit provides real focus", he said, in an apparently new-minted metaphor.

"People know what they agree here they'll have to deliver on."

'Ecstatic' reception

That said, he swept on and we trailed in his wake, to a tree-planting on the edge of a cricket ground by a cemetery.

The helpful lady from the Alexandra Regeneration Project was ecstatic.

"This visit has been fantastic", she told BBC News Online. "It's put Alex on the map. It's one thing to show all the poverty here, but quite another to tell people the good things that are being done."

Tumi Darlington, a 24-year-old community volunteer, was another fan.

"Alex needs a little bit of development and something done about crime", he said.

"If Tony Blair stood for election here, I'd vote for him."

Stinking sewage

By now Mr Blair was telling a large audience in a marquee that Alex and South Africa were both getting better.

"One thing is clear from the summit", he told them. "Where there's a will there's a way; where there's determination there's hope; where there's hope we can make things happen."

But it was time to go, 65 minutes after arriving in Alex.

And Mr Blair hadn't managed to see its really poor houses, or its stinking open pits of sewage, or the dereliction of its squatters.