My first real out-of-country adventures occurred in Mexico, on a family vacation to Cancun. When your mother was a Spanish teacher and knew Cancun before the massive development, and with a childhood of educational trips, it was clear we would not spend the whole time on the beach.
One of these adventures was a bus tour from Cancun to the Mayan site Chichen Itza, famous for its nearly perfect proportions in accordance with the sun, and other things like echos, a game court and sacrifices, all surrounding El Castillo. The guided tour I took here is the best guided tour I have ever had. Usually, I despise them. But on this tour I actually learned things and still remember them.
The most useful thing I learned that day was how to properly climb the steps to the top of the pyramid. The pyramid is at a 53 degree angle, while the stairs are at a 45 degree angle. The king would have to ascend these stair to the temple on top and he would be carrying offerings and wearing all sorts of ornamental objects. Not only would it be hot out, but he had to make it to the top with all sorts of things. The easiest way was crisscrossing back and forth across the steps. To descend, many people scooted down the steps, one by one, like a child.
There are a couple of other things I remember from this day, as well. One is that it was extremely hot that day, and I compare all excessively hot days to that day at Chichen Itza in June 2005. My day in Dubrovnik, Croatia, in May 2009, comes the closest.