How did you get the visa for the Tibet?
Hello Agustin,
first of all you need a visa for China, which is the most important one. For Tibet you will need a
Permit , which you will get normally from a tour-operator, which is handling travels inside China. As fas as I know there is no travel-agent outside China which is issuing such permits, which means you can get it only in China. To get one you have to book at least a package tour which can be arranged with your ideas. But to do so it can become expensive. That was the official version of entering Tibet. The inofficial is: do it without a permit, but on your own risk!
Bernd