Although I'm reasonably familiar with Greenwich, I hadn't come across anywhere called the Pagan Stone. However, I can think of a few sites that might fit the description.
A likely candidate is the stone fountain in Greenwich Park which is sometimes called the Motherstone Fountain or Mother Well. You can see it in a photo at the top (and it also appears on the cover of a book I've mentioned below). It was built in the 1860s to offer public drinking water, but some pagans believe the stone used might have been taken from an ancient megalithic monument. I'm not sure if there's any evidence to back this story up, but it does add mystery to the site. I know the fountain has been used for rituals to honour the Mother Goddess over the years. When I first saw it, in 2009, it was a beautiful place. The last time I was there the water was no longer running and it was a bit overgrown, but still had a lovely energy. I'm not sure if it's been restored more recently.blogged about that in 2019. There's only a plaque there now, but I recall many years ago a stone in the ground marked the spot. It was surrounded by Victorian railings. The stone marker might possibly have been called the Pagan Stone by some, but it wasn't actually ancient or part of the original temple. The picture to the left shows what the area looked like in 2019, long after the railings were removed.
Anglo-Saxon pagan grave mounds in the park are another possibility. There aren't any obvious stones there that I know of, just grassy mounds. Here's a link to a blog post I wrote about them. I had a long discussion with friends who know Greenwich and its history well and one of them vaguely recalled the graves might have been called pagan stones by some groups. You can see a photo of the grassy mounds below right.Goddesses, Guardians and Groves by Jack Gale. He mentions a historic sunken trackway running between the graves up to a site that is now a covered reservoir. According to Jack, a psychic told him the track once led to a standing stone dedicated to Odin, called the Odin Stone. If it ever existed it vanished centuries ago, but the grassland encircled by trees on top of the reservoir could possibly be a place pagans might still honour the Norse god.
Jack's book also mentions a public space called The Point, on Blackheath Hill. A road running around it is called Maidenstone Hill, which might have related to a stone that once stood on the green. Again, if there was ever a sacred stone there, it vanished centuries ago. A friend of mine also pointed out to me the Boundary Stone on Blackheath Hill, not far from The Point. It dates to the early 19th century and is listed. You can find a link to more about that here.
A few other friends said that the name "Pagan Stone" seemed vaguely familiar, but they couldn't recall exactly what book they had read it in or who they had heard mention it. If you know anything about a site in or near Greenwich called the Pagan Stone, please leave a comment. It would also be great if you know of a book, website or TV programme it's mentioned in.
Other previous related posts