Final answer:
Italy's historic and cultural significance, exemplified by cities like Florence and Venice, likely places several of its attractions among the top-15 worldwide, but the exact number is not provided in the information available.
Step-by-step explanation:
Italy is a country rich in culture, history, and heritage, making it a massive draw for tourists globally. Among the top-15 tourist attractions worldwide, Italy is home to a number of them. Cities like Florence and Venice are quintessential examples of Italian allure with their unique characteristics that encapsulate Italy's charm.
Florence, which is the birthplace of the Renaissance, offers immense cultural wealth with its architecture and art, being a UNESCO World Heritage Site. Venice is renowned for its romantic appeal and its unique urban fabric, consisting of canals running through the grid of small islands that comprise the city.
Although the exact number of top-15 tourist attractions in Italy is not directly provided in the given information, knowing the historical and cultural importance of Italian cities highlighted, it is likely that Italy boasts several attractions within that list. Whether or not this number is 2, 4, or 6 would require specific tourism ranking data which is not available here.