Which would it be? Say that you didn't have to worry about expenses. Someone else was covering air fare, hotel accommodations, meals & anything else you might need. You could only go to one place, though. This might be difficult to decide. There are so many well known landmarks in the world. Filled with history, even perhaps, some mystery & romance, depending on how it's viewed.
As mentioned previously, especially due to health issues, my husband & I have only traveled, very slightly, on the West Coast (US). There are many other states we'd love to see & countries to visit. If we could only select one, it would be Italy. He's part Italian (paternal grandma from Sicily, paternal grandpa from Naples) & even before we met, I had an interest in it. The food, culture, history, to name a few. We don't just want to check out tourist attractions. We'd also like to see how the locals live & enjoy some of the everyday events.
If we're going to Italy, of course one of the things we'd need to see would be, the Leaning Tower of Pisa. It's a freestanding bell tower of the cathedral in the city of Pisa. It's familiar, all over the world, for it's tilt. Which was not part of the original design. The tower is set behind the Pisa Cathedral. It's the third oldest structure in the city's Cathedral Square (Piazza del Duomo). The first being the cathedral itself & the second, the Pisa Baptistry.
The tower's slant began during construction in the 12th century. This was caused by an inadequate base. The ground being too soft on one side to properly support the structure's weight. The incline increased in the decades before the structure was finally completed during the 14th century. It continued to surge until the edifice was stabilized (and the tilt partially corrected) by efforts in the late 20th and early 21st centuries.
The height of the tower is 183.27 feet from the ground on the low side. It's 185.93 feet on the high side. The width of the walls at the base 8 ft 0.06 in. Its weight is assessed at 16,000 short tons . The tower has 296 or 294 steps; the seventh floor has two fewer steps on the north-facing staircase. Though I've changed some of the wording, the previous facts about the Tower were found on Wiki --https://en.wikipedia.org/wiki/Leaning_Tower_of_Pisa I just shared a little information. To learn more, you're welcome to check out that link.