Started in the 9th Century, Basilica di San Marco's architecture shows an eastern and Byzantine influence: note the golden altarpiece and the 13th and 14th-century mosaics that illustrate the cycles of the Bible. The magnificent domes date from the 12th Century. The Basilica houses the Marciano Museum, which contains the original bronze horses, copies of which are now on the terrace. Other great artworks are located in the Pala d'Oro , along with masterpieces of Gothic gold-smithing, located just behind the altar. At hundreds of years in the making, this beautiful basilica is not just a work of art itself, but houses some of the most important works of art in the world. Step inside (though mind the dress code) to marvel at the golden altarpiece, the mosaics dating back to the 13th century and which portray the cycles of the Bible, and the jaw-dropping domes. The basilica also houses the Marciano Museum and a wonderful display of the most amazing goldsmith work of the Gothic era.