National Traveling Salesman Problems

We list below 25 TSP instances taken from the World TSP.For these instances, the cost of travel between cities is specified by the Eulidean distance rounded to the nearest whole number (the TSPLIB EUC_2D-norm). The TSPs range in size from 29 cities in Western Sahara to 71,009 cities in China; they provide additional tests to complement the TSPLIB collection.

http://www.math.uwaterloo.ca/tsp/world/countries.html