Vatican City may be small, but it’s steeped in religious history.It has a long history of being strongly linked with Christianity as the site of Saint Peter’s tomb as well as being filled with famous churches, museums and beautiful gardens that millions visit every year. Vatican City was designated a UNESCO World Heritage Site in 1984. It became an independent state in February 1929, as defined by the Lateran Treaty. Vatican City is deemed the smallest country in the world. The city-state in Italy is landlocked in Rome and operates with its own telephone system, post office, gardens, radio station and more, per Britannica. Most of the supplies that Vatican City uses to remain functional are imported. Vatican City is the world’s smallest country. (Riccardo De Luca/Anadolu via Getty Images)A GUIDE TO VISITING ROME: HOW TO PREPARE FOR TRAVEL AND MUST-SEE SPOTSVatican City is just around 100 acres. The pope is the ruler of Vatican City and the Holy See, which is the government of the Catholic Church. The official residence of the pope is the Apostolic Palace in Vatican City. The Apostolic Palace is a popular destination for tourists to visit on their travels there as parts of the residence are open for the public to explore. One popular part of the palace to visit is the Sistine Chapel.  St. Peter’s Basilica is one of the most popular places for tourists to visit when traveling to Vatican City. (Stefano Costantino/SOPA Images/LightRocket via Getty Images)A GUIDE TO SIGHTSEEING IN ITALY: A ROMAN ADVENTURE AWAITS YOUSt. Peter’s Basilica is a must-see destination in Vatican City. St. Peter’s Basilica was completed in 1615 under Paul V, according to Britannica. It’s one of the largest churches in the world. It is full of breathtaking architecture, holy relics and beautiful artwork. You can purchase tickets for a self-guided or guided tour of St. Peter’s Basilica.While visiting, make sure to display proper decorum by wearing long or below-knee trousers, skirts below the knee and shirts that cover shoulders, the church’s website explains.  The Swiss Guard is responsible for the safety of the pope. (TIZIANA FABI/AFP via Getty Images)CHURCH IN SYRIA WIDELY CONSIDERED OLDEST IN THE WORLD; DURA-EUROPOS IS A HISTORICAL LANDMARKVisiting the Gardens of Vatican City, exploring St. Peter’s Square and enjoying a tour of the Vatican Museums are all worth the time during your trip. While traveling around Vatican City, you’ll likely see the Swiss Guard at their posts. The Swiss Guard is the private security for the pope. They have been in charge of the safety of the pope since 1506.  Once you fly into Rome, you have multiple transportation options to get you to Vatican City. (Thierry Monasse/Getty Images)CLICK HERE TO GET THE FOX NEWS APP Rome has two major airports you can fly into if you are planning a visit to Vatican City. One is Rome-Fiumicino Airport (FCO), and the other is Ciampino Airport (CIA). Once you’ve touched down in Rome, you can get to Vatican City by means of the metro, train or bus.  Ashlyn Messier is a writer for Fox News Digital.