Open a land object. For more information on how to do so, see section 10.1.
Go to the land card (see image below).
Click "More options" (see the first image below). When you do so, a menu will open (see the second image below).
Click "Delete land object" in the menu (see the first image below). When you do so, a dialog asking the following question will open: "Are you sure you want to delete this land object?" (see the second image below).
Click "Delete" in the dialog (see image below). When you do so, the land object you are working with will be removed from Pythagoras Web.