When you want to take an international tour, there are certainly plenty of travel agencies offering different experiences. What you may find as you peruse your options is that tours always have some sort of approach or theme. The purpose is to attract a specific group of tourists, and/or appeal to a different type of people. The following reveals what approaches are most commonly used, and why they might appeal to you.

Christian Tours

Christian tours, like Christian tours of Italy or Christian tours of Jerusalem and the Middle East, are meant to draw church groups or Christian individuals on personal "pilgrimages." These tours include stops in Rome to see the Vatican and the art displayed there, or at the place believed to be the spot where Christ was born. (While there is no barn, stable, or manager located at this spot, a holy structure has been built over the spot presumed to have been where the stable/manager once sat.)

Art Tours

So much art has survived the last thousand-plus years, and much of it is housed in galleries and museums across the globe. Those deeply interested in art and/or in its historical value gravitate toward these artistic tours. Many of them cover a new gallery or museum each day, providing you with lots of time to walk through each and explore all of the art at your leisure.

History Tours

History tours focus on certain time periods in history. Those fascinated with the Crusades or with the Renaissance can take a tour of multiple sites important to these time periods and cross through multiple countries. Sometimes, history tours examine the succession of kings and tour the holdings of former royalty. 

Castle or Famous Landmark Tours

Other tours offered provide you with in-depth tours of famous landmarks in this or that country. You can see London Bridge, Tower Bridge, the Tower of London, and Buckingham Palace in one trip to London. You could see the Louvre, the Eiffel Tower, and the Palace of Versailles in Paris. Some of these iconic landmark tours cover more than one major city in more than one country. 

Of course, you could always tour nothing but castles and vineyards too. These very popular tours offer chances for visitors to spend the nights in castles after touring them during the day. For an added twist, some tourism companies offer haunted castle tours, where the castles are purportedly haunted but guests are encouraged to spend the night anyway.