During his reign, Pope John Paul II has made more foreign trips than all previous popes put together. While some of his trips (such as to the United States and the Holy Land) were to places previously visited by Pope Paul VI ("The Pilgrim Pope"), many others were to places that no pope had ever visited before.
He became the first reigning pope to travel to the United Kingdom, where he met Queen Elizabeth II, the Supreme Governor of the Church of England. In a dramatic symbolic gesture, he knelt in prayer alongside the then Archbishop of Canterbury, Robert Runcie in the See of the Church of England,Canterbury Cathedral, founded by Augustine of Canterbury.
Throughout his trips, he stressed his devotion to the Blessed Virgin Mary through visits to various shrines to the Virgin Mary, notably Knock in the Republic of Ireland, Fátima in Portugal, Guadalupe in Mexico, and Lourdes in France. His public visits were centered around large Papal Masses; one million people, one quarter of the population of the island of Ireland, attended his Mass in Phoenix Park in 1979.
There was a plot to assassinate the Pope during his visit to Manila in January 1995, as part of Operation Bojinka, a mass terrorist attack that was developed by Al-Qaida members Ramzi Yousef and Khalid Sheik Mohammed. A suicide bomber dressed up as a priest, and planned to use the disguise to get closer to the Pope's motorcade so that he could kill the Pope by detonating himself.
Before January 15, the day on which the men were to attack the Pope during his Philippine visit, an apartment fire brought investigators led by Aida Fariscal to Yousef's laptop computer, which had terrorist plans on it, as well as clothes and items that suggested an assassination plot. Yousef was arrested in Pakistan about a month later, but Khalid Sheik Mohammed was not arrested until 2003.
In 1999, John Paul II visited Romania and met with the local heads of the Orthodox church. Thus, he became the first Pope to visit a country with a mostly Orthodox population, ever since the East-West Schism in the 11th Century (1054).
Source: http://www.wikipedia.org contributed to this report