Tourism in the Middle Ages had a rather religious slant to it.

The main form of "vacation" could be considered pilgrimage, wherein a person went on a trip to a holy place or site. People undertook these journeys for a variety of faith reasons, from purely personal piety to a desire for a specific cure or aid to being ordered by a confessor to expiate a specific sin.

There were major tourist attractions that drew big crowds. Jerusalem, Rome, Santiago de Compostela, and Canterbury spring to mind.

While on pilgrimage people would follow specific paths and stop at specific other sites (lesser saint's sites, specific churches, towns and cities) on their way to the final destination. In many ways you can liken these trips to today's "road trip". There were guide books that pilgrims could use to find the best spots to visit, learn trivia, find hotels and the like. There were souvenirs, in this case small relics, such as vials of oil or dirt, or badges. There were guides, whose living came from being able to show pilgrims the way and keep them safe and happy. And there were chartered trips, where a group of people would band together.

Rome is a great example of a tourist spot. We know that pilgrims came both to see the major religious spots (say the tombs of Peter and Paul, the Papal court etc.) but they also would have visited ancient sites like Trajan's pillar or the Colosseum. Rosamund McKitterick's Perceptions of the Past in the Early Middle Ages has a chapter on guide books to Rome that give factoids about various important sites in Rome. There were hostels, often based on region/national identity where pilgrims and visitors could stay.

And of course the pilgrims behaved like tourists, rude and annoying and "on vacation", essentially they could be seen to enter a different "state of being" while on pilgrimage.

As a side note, the Haj could be considered a similar sort of "tourist" spot for Muslims and the eastern world. We have several accounts of travelers seeing the sites on their way to and from Mecca.

Piggy-backing on what Mediaevumed already said, Medieval people traveled a lot for commerce as well. It was common for merchants in Barcelona or any other port to make trips to Egypt, Constantinople, or the Levant maybe once a year. If they were just going to North Africa, maybe more than than once a year.

These trips included staying in "fondacos" (medieval hostels). Port towns (even in the Islamic world) were rife with drinking, gambling, and prostitution. It could also include pilgrimages (perhaps the morning after drinking and whoring?); I mean, if you're already in Constantinople for business, why not see the famous sites?

Medieval people got around.

A really interesting, but super dense book, is Housing the Stranger in the Mediterranean World, by Olivia Remie Constable. It's basically a book about the "tourist" industry of the pre-modern mediterranean, but more focused on the institutions in place around commerce.