Ellesmere in Shropshire is drawing visitors from as far away as Cornwall to view the chicks at the Heronwatch project.
Cameras around the nests and a telescope at the visitor centre give nature lovers a close-up view of herons and their young.
The project is manned by volunteers throughout the breeding season.
The Boathouse Visitor Centre at the mere is open for viewing from 1000 to 1700 BST for the next few weeks.
The birds first started nesting on Moscow Island in the Mere about 40 years ago and return each year to the heronry high up in the trees.
Heronwatch was set up with funding from the Big Lottery Fund and the Heritage Lottery Fund through the Mere Heritage Restoration Project.
Volunteer John Smith said the grey heron was a very successful breeder.
"They haven't got any natural predators now that we've stopped eating them like they did in Henry VIII's time," he added.
"Where they nest the foxes can't get at them so they are virtually at the top of the food chain."
Visitor Andrew Taylor, from Barnsley, said: "It's fascinating. I've never seen anything like it before apart from on TV. It's nice to see it in real life. We get herons locally but I've never seen them nesting or with chicks."
Mr Smith said the ideal time to see the nesting herons and their chicks was over Easter before the vegetation on the island obscures the nests.