A pair of breeding peregrine falcons has set up nest at Gloucestershire Royal Hospital.
Staff have been using a mirror to monitor the birds which have settled on a ledge on the main tower block.
Three eggs have been laid in the nest and experts believe they could hatch in the next week.
The natural habitats of peregrine falcons are cliff faces, but there are increasing numbers being found in urban environments.
The hospital's senior estates manager, Terry Cockburn, said: "The eggs were laid at the end of April. They should be hatching about now and fledge hopefully in about July.
"That's when the fun starts, because that's when the youngsters learn how to hunt, they will chase things and the parents will bring things for them to eat."
He said the pair had opened up a new world to the staff who were learning about the birds and marvelling at their flight.
"And if you picture cliffs, the tower block and its manmade ledges resemble those in Cornwall, Wales or on quarries. These types of buildings are ideal for them," he added.