What is travel writing?

Travel writing is a broad and always shifting genre. A journal and even the captivity literature - as dramatic as it is - are also forms of travel writing.  

Now most of what we have is tourism related, but travel literature didn't begin with tourism. It began with pilgrims and immigrants. Many advice to differentiate the traveler from the tourist, because the second one is the Flâneur of our times, a casual stroller. 

Curious that many old travel stories were works of fiction based on real stuff. And sometimes the tales were not written by the protagonists. For example, the writer of romances Rustichello da Pisa wrote the travel stories of Marco Polo. 

Some interesting cases:

• The travels of the Galician Egeria to the Holy Land in the 4th century.
• The Basque Catalina de Erauso.
• Swiss adventurer Isabelle Eberhardt.
• Mandeville's The Travels of Sir John Mandeville.
  
• Thomas More's Utopia.
  
  

There is no foreign land; it is only the traveler that is foreign.

          Robert Louis Stevenson, The Silverado Squatters.  

References: 

Peter Hume and Tim Youngs, The Cambridge Companion to Travel Writing. 

Mary Baine Campbell, "Travel Writing and its Theory"