Are you ready for the challenge of climbing the 159 Welsh Marilyns (y Marilynau)? Marilyns are hills that are 150m higher than the surrounding land. Track your progress on your own personal log and with an interactive map from OpenStreetMap.
The Marilyn classification was created by Alan Dawson in his 1992 book The Relative Hills of Britain.
The Yr Marilyns app is brought to you by the Relative Hills Society.