Land access is a complex issue and the law varies Scotland and England are separate legal entities.
I'm Scottish myself so much more familiar with Scots Law but I am pretty sure land access is less rather than more permissive south of the border.
In terms of Scotland a quick google brings up this list of exceptions to access
Where do access rights not apply?
on 02 August 2008.
The main places where access rights are not exercisable are:
· Houses and other residences, and sufficient space around them to give residents reasonable privacy and lack of disturbance this will often be the garden area.
· Other buildings, works and structures, and the areas around them (curtilages).
· Land where crops are growing. Grass is not treated as a crop, except hay and silage in the late stages of growth. You can exercise access rights on field margins.
· Land next to and used by a school.
· Places, such as visitor attractions, which charge for entry.
· Land on which building or engineering works are being carried out, or which is being used for mineral working or quarrying.
· Land developed and in use for a particular recreational purpose, where the exercise of access rights would interfere with this use.
· Land set out for a particular recreational purpose or as a sports or playing field, when it is being used for that purpose and exercise of the rights would interfere with the use. But rights never apply to specially prepared sports surfaces golf greens, tennis courts or bowling greens
I would suggest women only areas may be permissible under this exception
Land developed and in use for a particular recreational purpose, where the exercise of access rights would interfere with this use.
But, it is the sort of thing that could potentially be challenged in court.