Before you ever put an offer on a property you're going to want your Realtor to obtain a copy of the title search for that property from the land titles office. The title search contains some vital information that you will need to know such as:
Who the registered owner or owners of the property are.  What type of encumbrances are charged against the title. There are 2 types: Financial - The most common being a bank where the owner has a mortgage. Financial charges are fairly easy to remove from title. The second type is a  physical encumbrance, these usually can never be removed from title. They are known as Inter Alia or they run with the land. It's critical that your Realtor do some investigating on these physical charges against title as some may affect the value of the land you are looking to purchase.