Six people queued in the spring sunshine at 7am on Saturday morning to be among the first to visit The Castle, the new leisure centre at Elephant & Castle.
Nearly four years have passed since the old leisure centre closed its doors to make way for the One The Elephant block of luxury flats and the new swimming pool and fitness centre.
Although the council promised that the much-delayed £20 million leisure centre would finally open in April, not everything was ready for Saturday.
"Unfortunately we still have some final checks to complete in the learner pool, but hope to get this open shortly," said the council in a statement on its website.
"We would like to thank you in advance for your patience and in the meantime, we would encourage residents of all ages to use the main pool and enjoy all the other fantastic facilities and classes on offer."
After this weekend's soft launch, a bigger event to mark the opening of the centre will be held in May.