The phrase "to travel" in Spanish is "viajar." This verb is commonly used in various contexts related to traveling, whether it's for leisure, work, or any other purpose.
For example, you could say "Me gusta viajar" which means "I like to travel." If you want to use it in a sentence about future travel plans, you might say "Voy a viajar a España," meaning "I am going to travel to Spain."
If you're looking for specific phrases or additional contexts where "viajar" is used, feel free to ask!