Thank you for the responses. Much appreciated.
Clarification - Since several commented on this I want to be clear, as stated in the first posting, "A surveyor confirmed the monument is accurate and does mark the property line". Also, I have the parcel map and even before the surveyor came out...
My mom's residential property in San Diego, purchased 2 years ago, is separated from the neighbor's property by retaining walls on both the north and south side. The north side is higher up the hill, the south side lower down the hill. The home is over 50 years old and the retaining walls are...