The antics emerged in a series of posts on Instagram over the weekend under the hashtag #sevensisters.
Cliff collapses in the area have been regularly reported this year and in May remarkable footage showed a huge chunk of a 250ft tall chalk cliff fall into the sea.
Thousands of tons of the rock were lost in the landslide, which is thought to have moved that stretch of coastline back around ten metres - but the latest photo over the weekend has prompted fresh warnings.
The cliff edge at Seven Sisters is not fenced off.
A spokesman for Dover Coastguard, which patrols the area, said: "There is nothing we can do to stop them doing it, but we do advise and request people not to do it.
"It's a problem and you can only tell people not to do it. It's a beauty spot and people do take pictures there, but there are signs up warning people not to go near the edge.
"Education is the best thing we can do."
A spokeswoman for Solent Coastguard added: "We've seen a number of cliff collapses around the coast in recent months and it's very clear that these cliffs are very unstable in places.
"We really can't stress enough how important it is to keep back from the edge. There is no safe place to be.
"Don't be tempted to go and investigate and don't risk going to the edge to get a dramatic picture - no selfie or photograph is worth risking your life for.
"Use the designated paths, take notice of any warning signs, be responsible and don't take any unnecessary risks."
It's not known if the tourists in the social media posts were on a group outing together. There have been record levels of coastal erosion over the last few years in the area, with increasingly frequent storms softening up the chalk cliffs.
This has resulted in dramatic collapses along the stretch, notably at Birling Gap where the National Trust cafe has had to be moved back from the edge.
Bob Jeffery, from Eastbourne Royal National Lifeboat Institution (RNLI), warned it is just a matter of time before the piece of cliff in one of the photographs collapsed.
He said: "You can see it is like a ledge and you can see where the cracks are forming. Once there are cracks it is only a matter time before it goes and if you happen to be on the edge at that moment you are not going to survive."
It is estimated that around 10 inches of rock are lost along the Seven Sisters each year. However, bigger chunks have been known to disappear into the sea in one fall following particularly bad storms.
Recent campaigns have aimed to highlight the dangers of posing for photographs on cliff edges with the National Accident Helpline's #SelfieSafety launched in October.
In March this year, a female photographer wearing a bright red jacket was criticised for sitting on the edge of the 530ft high Birling Gap.
Last year, a group of teenagers took it in turns to sit, stand and even lie on the edge of a cliff nearby with a 200ft drop below, and was photographed by retired teaching assistant Pearl Carter.
She said: "We were horrified. It was terrifying. The height down to the beach, if they had fallen, would have killed them."
Earlier that summer, a group of teenagers were also seen relaxing on a crumbly 300ft high ledge. In 2014, a man was spotted posing for a picture while dangling his legs over the cliff at nearby Beachy Head.
This article was originally published by The Telegraph.
