Drilling machinery has finished the vertical tunnel to reach a 2-year-old boy who fell into a narrow, deep borehole in Spain nine days ago.
Rescuers have said they hope to find Julen Rosello at a depth of 72 metres, where soil has blocked the borehole.
There has been no contact made with the boy, who fell into the 110-metre deep shaft during a family meal in the countryside northeast of Malaga more than a week ago.
Authorities said it had been a complicated drilling, which had so far taken experts 55 hours.
A drill that had been used to create that vertical shaft parallel to the waterhole has hit patches of increasingly hard rock.
Now the priority is to secure the tunnel through the cladding work and filling tasks.
"We estimate that this entire operation can be completed approximately in 12 or 14 hours", explained the leading engineer coordinating the search-and-rescue operation Angel Garcia.
If conditions are favourable, mining rescue experts will go down on Wednesday.
A specially-made cage has arrived at the site, ready to lower them down the shaft.
The experts will then start digging a horizontal tunnel to the spot where they believe the boy is trapped in the borehole.
At just 25 centimetres wide, the borehole is too narrow for adults to enter.
The only sign of the toddler search-and-rescue teams have found so far is hair that matched his DNA inside the hole.