On the wall above my desk at home is a framed map, circa 1887, that charts the distribution of rainfall over the globe. Its edges are slightly browned, but the colours are beautifully preserved: a pale mint-green for 'Rain at all Seasons of the Year'; a deep, inky purple for 'Australian Monsoon Region'; a heavy, fingerprint-like cross-hatching for 'Regions of Annual Rains of over 47 inches'.

The variety of colours helps define the myriad landscapes to which we travel. A drizzly day in San Francisco, where I live, tells me that all is as it should be, falling as the city does under the sky-blue swath of 'Subtropical Rains'. The famous fog rolls in, greening the hills. Eventually, the dry, bright spring arrives, covering the coast with the orange bloom of California poppies, the seemingly endless season bookended by the heat of September's Indian summer.

Before it became so easy for us to get to distant places, a map constituted a virtual trip. Though Google Earth can now zoom me from California to Cambodia at a moment's notice, I still prefer travelling by way of the paper maps that littered my childhood, in the form of fold-outs falling from old issues of National Geographic or specially ordered road atlases arriving in the mail. There was an added dimension to be puzzled over: charts depicting grain output in sub-Saharan Africa, or a prediction of when we would pass Niagara Falls on the way to visit relatives in Toronto. The charts and maps helped to tell a story: that crop shortages required advance humanitarian aid, that it would take us 12 hours to get to my grandfather's house. Either way, we'd all best get started early.

My fiancé's stepfather, Jan, once gave me a vintage 1873 polar projection map of Asia in which Japan was Niphon, Iran was Persia, and the Chinese and Russian Empires muscled up against an Independent Tartary. Being a ship surveyor, Jan is understandably a bit of a map freak. We examined the lithograph, observing the configuration of a world long gone: Thibet a separate green-grey, encircled by reds and blues colouring China, the Chinese Tartary, and the Chinese Empire. It was easy to read the surrounding entities in the context of what we already knew—every empire ready, jockeying for influence. The Americas, a yawning half-spin of the globe away, weren't even in the picture. The story told by that map was embellished by history, actual experience, and our imaginations. For a little while, we could be lured to time-travel.

On most days, I use maps the way everyone else uses them, the way they were meant to be used—to get somewhere. Trail maps have their own section in my library, next to guidebooks stuffed with discrete folding accordions of London and Paris (annotated with favourite restaurants) and island maps of Hawaii (annotated with red dirt). In Don Quixote, Cervantes wrote that one can 'journey over all the universe in a map'. Sometimes the most interesting thing about a map isn't what's there, but where it leads us, beyond its edges.

Bonnie Tsui is the editor of the essay collection A Leaky Tent Is a Piece of Paradise: 20 Young Writers on Finding a Place in the Natural World (Sierra Club Books, £12.95)