The big US history tour missed the top sites in Baltimore, home of Edger Allan Poe. The data set included the listings for Baltimore County, but the listings for the city itself were tucked away in five separate directories. Again, sorry Ravens fans!

We have to visit Baltimore, so I computed an optimal side-trip to get you to Poe's house and each of the other 288 sites listed in the National Register of Historic Places. The TSP in this case was not much of a challenge for our machinery. It solved in only 0.7 seconds on my Mac Mini. The walking tour covers 202,685 meters, or 126 miles. So a tough weekend challenge, even if you have a new pair of Converse All Stars.

You can click here for an interactive Google Map of the tour, or here for a list of the stops in the optimal order.