Depending upon the nature of the adjoining property, you may be able to assert a possessory title claim over the area of the adjoining property that your fence encloses. If the adjoining property is a park or other Crown-owned lands, the test to assert a claim for adverse possession is much more difficult. If the adjoining lands are privately owned, generally you must establish that you have used the property for at least 10 years, that you have actually been in possession of the property, and that your use has been exclusive, open, and continuous without the permission of the owner. You must also show that you used the property with the intention of excluding the true owner from his or her intended use of the property. If the adjoining lands are registered within the Land Titles Absolute system in the applicable Land Registry Office, your potential claim will be barred unless it crystallized before that registration. If the possessory title claim is not available, it may be possible to enter into an encroachment agreement to allow the fence to remain.