In the Letter to the Romans, Paul expresses his desire to go to Spain to preach the Gospel there. However, the Acts of the Apostles do not describe this event, so we are not able to clearly state whether it took place on the basis of the Bible. This article aims to present the evidence that proves it was carried out. The first part presents the indirect evidence found in the New Testament - determination to reach new cities and win the trial. Then, texts from the broadly understood tradition are presented. They clearly confirm the trip and provide a number of details, which proves their credibility. The third part contains knowledge of history and archeology. It allows to determine the probability of crossing to the Iberian Peninsula in the 1st century AD. Presented legends and artifacts confirm the possibility of the Apostle of the Nations preaching on the Iberian Peninsula. However, he had to obtain logistical, linguistic, and financial support from Christians living in Rome.