The Countryside Agency is printing open access maps for the whole of England over the next 15 months. The first ones cover the south east and the lower north west, which includes the Peak District, and will be greeted eagerly by ramblers.
But some landowners are worried that incorrect areas will be included and that farmland will be damaged. Any private land considered moor, heath, mountain or downland or registered common land will now be open to walkers.
Ramblers groups are jubilant and have called these maps the most exciting development since the creation of national parks after World War II.
But opponents say consultation has been scant, decisions on what constitutes open access land have been bizarre in some cases and the appeals process has been time-consuming and costly.
The new laws do not give people a right to roam anywhere. Areas like gardens and cultivated land are not included and there are restrictions on some areas at certain parts of year.
A total of 105,253 hectares of new access land has been opened this week – 13,853 in south east England and 91,400 in the lower north west. Other areas will then follow suit.
Walkers have turned out to mark the introduction of the Countryside and Rights of Way Act.
Nick Barrett, chief executive of the Ramblers Association, said: “This is a truly historic day. These landscapes are as much a part of our national heritage as structures like Stonehenge.”
The success for ramblers comes after years of lobbying and direct action in an effort to get access.