BBC Wales Environment Correspondent
Which parts of the Welsh coast should we fight to save for future generations, and which parts should disappear into the sea?
Pembrokeshire owes its beauty to the battering of wind and waves
That is the the question being posed by academics and government agencies as they carry out a review of the effects of coastal erosion.
It is a question which has particular significance for Anwen Owens who farms and runs a caravan park at Pistyll near Nefyn in north west Wales.
She is still shocked by her memory of a day in 1998 when eight acres of her land slipped into the sea during a storm.
Caravan park owner Anwen Owens who lost land to the sea
"It's an awful lot of land to lose in one go," she recalled.
"But I remember my father saying that when he was a boy 70 or 80 years ago, he came home for lunch after ploughing and when he got back the field had gone. So I suppose it's nothing new."
And of course, coastal erosion is nothing new.
It is why the coast of Wales looks the way it does. Whether it is the dramatic plunges of Pembrokeshire or the sand dunes of Flintshire, they are there because of the constant battering of wave and wind.
Newborough on Anglesey is one of Wales' most beautiful beaches.
Part of Newborough beach is eroding a metre a year
Framed by Snowdonia on one side and a sweeping bay on the other, a pine forest lines a duned shoreline.
But at one end of the beach the coast is eroding at a rate of one metre a year. At the other the dunes are growing.
"People have to remember these places are a product of natural processes," said Countryside Council for Wales warden Will Sandison.
"Soft coasts should be allowed to move backwards and forwards to form their own sea defence line," he added.
"All too often man has intervened by building a road or sea wall or whatever. Then the system breaks down."
In places our intervention and then failure to maintain it have had disastrous consequences.
At Towyn and Kinmel Bay on the north Wales coast, sea defences were built to protect the main Holyhead to London railway line.
Behind it, new settlements built up. Everything worked for decades until February 1990 when the sea wall failed in a storm.
The tide quite literally came in, forcing thousands of people to flee their homes.
There the sea wall has been rebuilt stronger and taller than ever. But for how much longer can we continue to take such measures?
It is predicted that climate change will bring more frequent extreme storms. Coupled with that, sea levels may rise by as much as 30cm in in the next 70 years.
The idea is to work with nature to protect places like Skomer Island
The present review of the entire Welsh coast will help decide which stretches are under greatest risk and how best to protect them.
But experts are also embracing a new thinking - 'managed retreat'.
This comes from acceptance that, in the end, mother nature will always win, so it is better to work with her than against.
On England's low-lying east coast they've gone a step further and deliberately broken down defences to let the tide reclaim land drained for centuries.
Nothing quite so dramatic is yet planned for Wales.
Here, in most cases, coastal land and property will continue to be defended in the traditional way.
But in future other stretches will be surrendered to the sea.
Policy makers see it as bowing to the inevitable and some tough choices will have to be made.