Introduction
This is a listing of sites that legally offer free books on Travel, for reading and listening (audio).
All of these sites listed have content that is legal to distribute. If you find that any site listed is offering content that can not be legally transferred, please let me know in the comments below.
This list is not comprehensive and if you know of any other sites please post in the comments below.
A comprehensive alphabetical listing of free books for reading or listening can be found on these pages:
There will be other books on Travel at the sites listed there, but they are not categorized at the sites.
Libraries are also an excellent source for reading and listening materials. To find out more information on your local library, the links here may help: Library Information [4]
There are 15 other book pages here at Gizmo's covering other various popular book genres and offering links to free online books listed here: Book Genre Pages [5]
Travel
2020k (Travel) [6] Large collection of links to books divided into categories and sub-categories. Varying formats.
ArtofTravel [7] 
offers the ebook, How to See the World, backpacking on $25 a day or less for free reading online.
BesteBooksWorld [8] offers links to over 300 travel ebooks in 8 categories. Since these are links offsite, the download and viewing options vary. I also found a few links in other genres that lead to spam sites, so watch where the links lead.
BookBoon [9] offers 8 free ebooks on travel to places around the globe. You must provide some information and email in order to get the download in pdf.
BookYards (Travel) [10] 130 books listed in categories available for pdf download
Bored.com (Travel) [11] has 164 travel books searchable by name available for online viewing.
ChestofBooks (Travel) [12] Around 50 books available for online viewing.
eBookLobby (Travel) [13] 17 books available in varying formats
eBooksForAll [14]offers links to 190 free travel ebooks. Download and viewing options vary as most of these link offsite. Some of these books are at sites listed here, but there are some unique entries also.
FreeeBooks.net (Travel) [15] 10 books available in pdf or html
FreeOnlineBookstore(Travel) [16] has a nice collection of ebooks referenced. These are links to sites around the web and the download and readin online options vary.
GoogleBookSearch (Travel) [17] 565 books available for online viewing
Gutenberg (Travel) [18] Large collection available in several formats
ManyBooks (Travel) [19] 724 books available for download in a large variety of formats
MichaelPalin [20] Former Python Michael Palin has made a name for himself lately as a brilliant travel-writer and has made six of his travel books available for online viewing. They are spread across many pages, so not very practical to download.
Moxon.net [21] About 20 ebooks representing writings from a travel writer's articles combined. Available for download in several formats
Munsey's (Travel) [22] 85 books available for download in a large variety of formats.
oBooko [23]has free ebooks on travel to Japan and Poland as well as a large number of guides to rural Scotland, England and Wales. These are available for download in pdf after free registration. I have received no spam from the registration.
ShadyMike [24]offers 4 free books on travel for download in pdf.
TravelandTransitions [25] offers several free ebooks for download in pdf. These are compilations of the writer's blog entries.
TripBase [26] offers 7 travel books for free download in pdf. These books are compilations of tips from over 200 travel bloggers. Also, TripBase will donate 50 cents to MyCharityWater [27] (helps provide clean drinking water to the over 1 billion people without) for every book downloaded.
Travel (audio)
LearnOutLoud [28] has 7 free audio books under its Travel category. They are available in different ways, including online listening, MP3 or MP4 as many link to other sites. Also, some video files here.
LibriVox [29] has 52 free audio books under its Travel genre available for download in MP3 (64kb/128kb) or ogg vorbis. All are human read.
MarkMoxonTravelWriting [30] a nice little collection of Mark Moxon's travel writings available for download in MP3 or AAC.
[31]