Isle of Man a British crown dependency in the Irish Sea, directly between Great Britain and Ireland
The Channel Islands are sometimes included in the term "British Isles" because they are a British crown dependency. However, they are located off the coast of Normandy, France, and are not geographically part of the British or Irish Isles.
A number of separate jurisdictions with their own immigration rules make up this region. So a traveller may wish to check the requirments for the territories in which they wish to travel, on the appropriate pages. However there is considerable co-operation and co-ordination between the authorities of the countries in this region meaning that the British and Irish Isles comprise a Common Travel Area, which helps the vast majority of travelers enjoy hassle free travel when crossing borders within the British and Irish Isles.
The arrangment's origins lie in the fact that whole of Island of Ireland was once part of the United Kingdom and so there was never a need for immigration control for what was at that time domestic travel. Whilst Ireland and the United Kingdom have been separate countries for many decades, for the most part both countries have found it more beneficial to maintain relatively open borders. However because of the way its history, the CTA arrangment is not as formalised as other similar arrangments (such as the Schengen Area), and so the exact rules are quite complex for some third country nationals. There are therefore some limited exceptions to the principle of complete freedom of travel.
Nationals of a "Common Travel Area", Country can travel to any of the others without a passport.
Visitors from other countries who have been checked through immigration in one part of the area (e.g. England) wouldn't normally have to go through immigration procedures when continuing a journey to another part of the Area (e.g. Ireland).
However only citizens of the European Economic Area have the right to travel between the two countries without a passport.
Visitors from a country needing a Visa to enter one Common Travel Area Country, but who is a resident in the other will generally need to apply for a Visa to enter the other. Whilst both countries have very similar Visa rules, it is important to remember that unlike the Schengen Area, the United Kingdom and Ireland maintain separate Visa systems.
Throughout this region, traffic drives on the left. In the United Kingdom, and its Crown Dependencies Speed Limits are expressed in Miles per hour. In the Republic of Ireland speed limits are expressed in Kilmometers per hour.