On a muddy peninsula on the Arade reservoir we watch police busily clearing a wooded area.
Every now and then they appear from beneath the trees with handfuls of branches. Later, a police dog is led into the area that had been cleared.
It's believed the prime suspect in the disappearance of Madeleine McCann frequently visited this spot.
As the day goes on, other officers dig into the dry earth. They are all hoping to uncover vital new evidence.
Christian B, a convicted sex offender, lived in the area when Madeleine went missing.
He has denied any involvement, but the police are revisiting his old haunts after a new tip off.
It's reported this new information came from an informant and is viewed as very "credible".
The tip was clearly detailed enough to launch the first search in Portugal for almost a decade.
Madeleine was three years old when she went missing from her hotel in Praia da Luz on the Algarve coast.
Sixteen years on and the town's name has become synonymous with the case.
British tourists Pat and Sheila have been visiting the area for decades and remember the day Madeleine was reported missing.
"We were here when it actually happened. It's very sad, the whole thing. For the McCanns, if they found something, it would be closure. I think that's the best thing and that the way I would look at it," says Pat.
Sheila tells us the local church still prays for Madeleine every week. They want to move on but the mystery of what happened to her still hangs over the area.
Many in the town are hoping this new search could finally bring the answers they crave.