Liverpool's Stanley Park, which underwent a £14m restoration a year ago, is one of 17 across the city to be awarded a Green Flag award.
The 111-acre park was re-landscaped and had its third lake reinstated, and its central 19th Century conservatory restored during the two-year project.
Green Flag awards are given annually in recognition of exceptional high quality green public spaces.
They are awarded by judges from government and conservation groups.
Liverpool City Council's cabinet member for the environment, Councillor Tim Moore, said: "It's wonderful that just one year after officially re-opening, Stanley Park can fly the green flag - it's the perfect birthday present to mark the hard work and commitment of all the team and community involved.
"We want to make sure our parks and gardens are places residents and visitors want to spend time in, and knowing that they have received national recognition for their excellence will hopefully encourage even more people to make the most of the green havens on their doorsteps."
The awards recognise achievements in conservation and heritage, community involvement, facilities, signage, health and safety, security and a sense of welcoming.
Paul Todd, of the Green Flag Award Scheme, said: "It's a remarkable achievement that so many Liverpool parks have successfully reached Green Flag Award status this year.
"As the recession bites and people look closer to home to enjoy the outdoors, the provision of high-quality, free open spaces is of particular importance."