Lugouqiao is called Marco Polo Bridge in English. It is a 12th century bridge over the Yongding River, famous both for the 500+ lions it is decorated with and being the site of the first open attack on China by the Japanese in the pre-WWII invasion of the country.
I had been here in 1988, when it was about 5k in what passed for the city then, and 35k in really pretty and interesting countryside. Those numbers have not remained constant - the approximate numbers now would be 40k city, 0k countryside. There were some new sights along the way: The second largest shopping mall in the world is along this route.
In all her time living in Beijing Hua Lin had never been there, so we decided to go on a deliciously cool fall day during the National Day celebration. It was a good route - because it is flat and the day was cool, Hua Lin finished it surprisingly easily, and she was impressed by the bridge and the city walls leading to it. It was the first trip I made with the help of my iphone and its gps. While using a gps is not as exciting as seat-of-the-pants navigation, when you are out with someone who is pushing her distance limit and you have the responsibility to lead the way, it is pretty good to have a live map to tell you which way to go.