When I travel I carry sketch pad and drawing materials. This can be uncomfortable, as in Venice perched on a wharf on the grand canal in mid winter with Elizabeth cursing me for drawing the most detailed building in Venice in the icy weather (ca d’oro from the wharf opposite in front of the fish markets). All of these are at a size of an A4 page or a little larger…for ease of carrying.
Other scenes invite drawing, less because of discomfort and more because of merit.
and some just make you hapy to draw
others allow you to rework space neatly in ink and wash
most of which present a classical problem of a depiction of space on a page.