Shared areas of a rental property

I moved into a privately rented annex on a farm 6 months ago with my partner. From the outset it was difficult to judge precisely what areas outside the property were “ours” to use, and which were our landlady, who lives next door. She was very happy for us to use the outbuildings to store bicycles etc.
Recently the landlady has allowed someone to camp on the field adjacent to our annex, which we are not particularly happy about. We also have an outside toilet that connects to our water/hot water supply, which the camper has taken to using. He also has several dogs that bark loudly through the night. As it was not clear from the outset of the contract what areas we are renting, I’m not sure on my rights as far as objecting to this. Could anyone advise as to this situation?

Many thanks,