I'm not sure why we went all the way to the National Zoo to see turtles. If you are careful and reasonably cautious, you can see turtles almost anywhere that happens to feature water and an absence of predators.
A good time was had by all. The National Zoo is a fantastic place. I cannot believe that this was the first time I had even been there. It compares favorably to the Wilhelma Zoo in Stuttgart, by the way (there, they have giraffes but no pandas).