Until extraterrestrial travel is a practical possibility for non-billionaires, Wikitravel is going to deal with travel on planet Earth (although there is a Space article for jaunts out of the atmosphere). We see a rough hierarchy of geographical areas in the world, detailed below. Each level of hierarchy probably deserves an article of some length on its own. The names are unfortunately kind of forced, but they're selected to be unique just to make it easy to follow.
Why do we have a geographical hierarchy in the first place? The point of the hierarchy is not to nitpick about geographical niceties, but to organize our work. What do we write Wikitravel articles about? What are the subjects of our discussions? What kind of article do I write about Topic X? When we have a hierarchy of geographical units, we can use them to identify things we write about, and thus how we write about them.
For example, consider Catalonia. By understanding the hierarchy, a contributor can know that Catalonia is a region. From there, they can figure out that the article about Catalonia should start with the region article template; that it should contain links to cities in Catalonia like Barcelona; and that there should be a link to the Catalonia article from its containing country, Spain. (Yes, this is a politically loaded example -- many Catalonians consider their region to be its own country). They also know what ''not'' to put in -- that information about money should go up at the country level, and that listings for individual restaurants and hotels should go down at the city level.
By having a hierarchy, we don't have to figure and refigure this stuff out over and over again for Normandy and The Lake District and New England and every other region in the world. Sure, there will be exceptions for every place, but by having rough guidelines, we can have a framework to make those exceptions against.
These levels of hierarchy aren't hard and fast, and they're open to revision. But it makes sense for articles at a given level of hierarchy to have links to the next level down in the hierarchy, and for articles at the same level of hierarchy to be about the same.
The Wikitravel geographical hierarchy goes like this:
Levels in the hierarchy can be skipped if they don't make sense. For example, the country of Andorra is only a few square miles in size; it would be laughable to write articles about its different regions.
'''Continents''' are big sections of the globe. We've started with Asia, Africa, North America, etc., and a separate pseudo-continent of Island nations. There's not actually much practical travel information that can be given on, say, Asia, but it does provide a convenient container for the next level of hierarchy.
A '''section''' is a division of a continent into a logical travel part. Classic examples are Southeast Asia or Northern Europe. Sometimes sections may not make sense, or may be equivalent to national boundaries. For example, it's natural to divide North America into Canada, the United States of America, Mexico, and Central America.
A '''country''' is a sovereign state territory on the globe, like Djibouti, France, or Brazil. Countries tend to be the level where information about currency, immigration, language, culture, etc. get described. This level cannot be skipped.
Some countries like Monaco or Singapore are so small that they can be considered single cities. In these cases, add city-level headings like "See" and "Do", and if the article grows large enough, divide them into city districts.
See also: Country article template
A '''region''' is a subnational division that is climatically, culturally, geographically, or politically coherent. Regions may lie along subnational borders -- like states in the USA, provinces in Canada, or departements in France -- but more often they are above this level. One could divide Vietnam, for example, into the North (Hanoi and environs), the Central Coast (Danang, Hoi An, Nha Trang), the Central Highlands (Dalat and nearby) and the South (Saigon and the Mekong Delta).
It's not impossible that regions would cross national borders -- the Himalayas would be a good example -- but the idea is to have travel divisions below the nation level. Also, bodies of water are usually ''not'' considered regions, but exceptions can be made on a case-by-case basis.
For large countries, regions can and should contain other regions, in order to make it easier to grasp. For example, the United States of America has 50 legal divisions -- more, if you count territories like the District of Columbia or Guam -- which is probably too many bits for people to grasp all at once. For the USA, we've divided the country up into about 10-12 regions, each of which in turn contains one or more of the U.S. states (which are themselves divided into regions). It may be reasonable to do this in other countries, although (as noted above) it's not always necessary to divide our regions along political boundaries.
See also: Region article template, Bodies of water
A '''city''' is, in reality, the unit of travel guide geography. It's where you arrive to, where you go see sights, where you find a hotel, where you eat in restaurants, where you move on from when you're done. Wikitravel's definition of a "city" is flexible: they may be literal incorporated ''cities'', but they can also be larger ''metropolitan areas'' with suburbs and satellite cities, like Los Angeles or Paris, or they can be smaller ''towns or villages'', like Zermatt or Panmunjeom. Where suburbs, satellite cities, and villages deserve their own Wikitravel entries is a matter of judgement -- probably depending on the amount of information about those places. We have different templates to deal with cities of different sizes and complexity.
Most information in Wikitravel will be about specific cities -- the practical dollars-and-addresses info. See What is an article? for help in drawing the line between cities and attractions in cities, as well as dealing with non-city destinations like national parks.
See also: small city article template, big city article template, huge city article template
Some cities are just so big and so diverse that there's too much information to keep in one Wikitravel article. It'd make sense, then, to divide the city again into '''districts''', so that practical info -- hotel listings, restaurants, bars, sightseeing attractions -- can get their due. Examples of districts in San Francisco would be San Francisco/Marina, San Francisco/Tenderloin, and San Francisco/Mission.
Whether to break down a city into districts is only a matter of content, not so really of the city's physical size. Lubbock, Texas is an awfully big city geographically, but it just doesn't have enough ''stuff'' to write about that would justify classifying it as a "huge" city and breaking it down into district articles.
Here's kind of a partial example to illustrate the hierarchical levels described above:
The hierarchy of each article is automatically displayed in the breadcrumb navigation menu below each article. For example, Castro Street's breadcrumb menu shows:
: North America : United States of America : California : Bay Area : San Francisco : Castro Street
Creating these menus requires entering the correct ''isPartOf'' tag, see breadcrumb navigation for the details.
Some of the geographical units in this hierarchy are easy to decide on, in that they have legal boundaries: cities and countries, for example. Others are so well accepted that it's hard to imagine them being controversial, such as continents. But the others – continental sections, regions, and city districts – have fuzzier boundaries and definitions. How, then, do we decide where to define them?
Some guidelines are:
Dividing geographical units is something of a dark art. Use caution, consensus, and collaboration when possible.
Once we have enough content for creating a district article, we want to make sure it's clear where all the information goes. Prior to adding district articles:
Once the new district articles have been created, all listings should moved to district articles. Consider putting the template '''<nowiki>{{districtify}}</nowiki>''' at the start of sections that need to be sorted into districts. This adds a message which encourages editors to move the content. Remove '''districtify''' when the content has been moved out.
The legal divisions in the geography of the world -- nations, provinces, and cities -- don't necessarily make for reasonable travel divisions. Just because some national government decided it would be easier to administer some swath of land by laying down lines on the official map doesn't mean that they deserve separate articles in Wikitravel. Yes, Baja California Norte and Baja California Sud are technically two different Mexican states, but for purposes of a Wikitravel article, it makes sense to combine them into Baja California.
In general, we try to avoid overlap between two destination guides, unless one destination contains the other. If we have overlapping guides, readers don't know where to go to get travel information, and contributors don't know where to put travel information. It's also easier to draw maps for a destination if none of the parts of the destination overlap.
No two regions at the same level of the hierarchy should overlap. Nonetheless, if a subregion is commonly understood as belonging to more than one parent region (e.g., Russia is in both Asia and Europe) it is perfectly fine to list it in both parent regions ''as long as this does not create significant content overlap''. A region's breadcrumb trail, however, will display only a single parent region in a strict hierarchical fashion.
Occasionally a well-defined region will straddle a political boundary between two countries, states, or provinces. It is usually preferable to deal with these instances as a single region, rather than dividing them up into unnatural, small pieces divided by the imaginary lines of borders. An example would be Lake Tahoe, a region between California and Nevada.
Regions and districts breakdowns should never leave any gaps. Wikitravel is a guide to the ''world'', and there should be a space to add content for travel advice on any destination on the planet.