either a matrix or data.frame with two columns, a list with components x and y, or an object of any class that can be used for maps and provides its own plot method (e.g., "SpatialPolygons" from package sp). A list of the previously mentioned types can also be provided.

a logical indicating whether map should be added to an already existing plot (the default is FALSE).

further arguments and graphical parameters to be passed to plot and/or graphics::lines().