It’s impossible not to feel awe-struck as you stand beneath the glowing, golden mosaics on the ceilings and walls of St Mark’s Basilica. For many tourists, seeing St Mark’s mosaics in-person is the highlight of their Venetian journey. Below are a few fascinating facts to help you better appreciate your time with these masterful mosaics.

1. One of the most impressive features of St. Mark’s mosaics is their massive size. It’s estimated these mosaics take up about 8,000 square meters of space. To help give you perspective, that’s equivalent to almost 2 US football fields.

2. When you enter the basilica, take a look at the mosaic directly over the left door. This mosaic, which dates back to the 13th century, depicts the adventures of a group of Venetians who stole St. Mark’s body from Egypt in the 9th century. Do you know how these Venetians got St. Mark’s body past the Muslim guards? They hid the body under pork!

3. Due to restoration work throughout the centuries, there are mosaics in St. Mark’s Basilica that date as far back as the 11th century and as recent as the 19th century. Today, a group called the Procuratoria of St. Mark continues to oversee all restoration projects on these mosaics.

4. A constant concern for preservationists working at St. Mark’s Basilica is the threat of flooding. Indeed, in October of 2018 the city suffered a major flood that covered St. Mark’s floor mosaics with three feet of seawater. Venetian officials are worried about the corrosive effect of the salt water could seriously alter the precious art in St. Mark’s over time.

5. Staff at the Basilica San Marco turn on interior lighting late in the day to help visitors appreciate the superb artistry of these mosaics. Tourists who want to avoid the crowds and enjoy these illumined mosaics should plan on visiting St. Mark’s at nighttime.

6. In the 16th and 17th centuries, many of Italy’s finest painters were asked to create cartoon designs for mosaic restoration work. A few of the most famous artists who worked on this project include Veronese, Tintoretto, and Titian. Indeed, you can find mosaics based on the cartoons of Titian in the sacristy area.

7. All of the cupola mosaics in the atrium were completed in the 13th century and depict different scenes from the Old Testament. As you look up at these mosaics, check out the depictions of the story of Creation, Abraham, Joseph, and Moses.

8. Sorry, you aren’t allowed to snap selfies with the mosaics of St. Mark’s Cathedral behind you. The Basilica San Marco forbids the use of photography inside the church.

9. Tourists looking for one of the oldest mosaics in St. Mark’s Basilica should walk around the entrance at the narthex and look for a large image of St. Mark with his hands outstretched. This St. Mark is from the 16th century, but the depiction of the Virgin Mary with baby Jesus and surrounding Apostles dates to the 11th century.

10. The techniques used to make Basilica San Marco’s oldest mosaics come from the 5th century BC in Ancient Greece. Interestingly, a few historians believe some of the earliest mosaics might have been completed in Constantinople before they were shipped to Venice.

Once you see the Basilica San Marco’s mosaics for yourself, you’ll understand why this church is called “The Golden Basilica.” Seeing St Mark s mosaics, as well as the many other treasures inside St. Mark’s Basilica, is an essential stop on any tour of Venice.