For this case the answer depends on the time for which the sentence will be written.
We have then:
Present time:
We travel to Mexico many times.
Past time:
We traveled to Mexico many times.
The translations in Spanish are given by:
Present time:
Nosotros viajamos a México muchas veces.
Past time:
Nosotros viajábamos a México muchas veces.
Answer:
Present: viajamos
Past: viajábamos