Buying a house with a private and unaccessible Right of Way

da_rule

If the square appears within your boundary on the Land Registry map then you own the property, with the other properties having an easement to allow them to use the square for storage of bins or what ever it may be.

If the fencing means that the other properties no longer have access to this square then you could apply to the land registry to have the easement extinguished. This would need to take the form of a statutory statement from yourself and the seller saying that in X number of years the people who benefit from this easement have not tried to use their right under the easement. This is known as abandonment.

You could also get the owners of the properties which benefit from the easement to sign a deed of release which will again mean the easement can again be extinguished.

As a side note, if the fence is blocking the square of land then the title may technically be defective and the people who benefit from the easement may be able to make a claim against you for preventing their use of the easement. I know this is VERY unlikely but just thought I'd throw it out there. It may be worth looking into defective title insurance (usually paid for by the seller) should the worst happen.