A new campaign group aims to protect the dwindling number of historic milestones along its highways.
The milestone's are difficult to steal because they weigh half a tonne
The number of milestones in Ceredigion has dropped from 200 at the start of the last century to about 100 now.
The Ceredigion Milestone Society now wants to ensure that the remaining stones are protected as part of the county's heritage.
In recent years a growing number of milestones, introduced in the 18th Century to help map out the expanding road network, have appeared on the antique markets and have fetched up to £400 a time.
Michael Freeman, curator of Aberystwyth-based Ceredigion museum, is one of four people who have joined together to set up the group as a branch of UK Milestone Society.
"This new branch will make a record of the remaining milestones and try and ensure their survival," said Mr Freeman.
Milestones were created after an Act of Parliament in the 1770s set out to improve the British road network.
The act resulted in the setting up of toll roads on main roads and milestones along the roadsides.
Many of the original milestones are still standing - including one on the road between Tregaron and Lampeter near Llangybi which dates back to the 1760s.
"Even though most of the milestones still standing only date back to the late 19th Century, it is still important for the heritage of Ceredigion to ensure their protection," Mr Freeman said.
Ceredigion had one surveyor for the north and south of the county which may have given rise to different milestone designs in these areas.
"Milestones in north Ceredigion are rounded at the top and smooth whereas those in the south are square shaped and rough," said Mr Freeman.
Milestones were dug up because of fears of a German invasion
Many of the county's milestone were lost after they were uprooted during World War II to stop any invading German army from finding their way around the country.
"Although more than 100 were replaced many must have been lost and we want to find out what happened to them," said Mr Freeman.
Mr Freeman believes few, if any, milestones had been stolen in Ceredigion during the last few years.
But it is a major concern for the Milestone Society, founded in 2001.
Secretary Terry Keegan said: " The loss of our milestone heritage through deliberate theft is a major concern of ours.
"Some milestones have appeared in architectural antique shops and are being sold at up to £400 each."
It was very difficult for people to steal the milestones because they weigh half a tonne, said Mr Keegan.
"Usually thefts have taken place when milestones have been loosened by roadworks."
The inaugural meeting of the Ceredigion branch of the society will take place on 15 March.