TUNE IN TONIGHT

THE NATIONAL PARKS: AMERICA'S BEST IDEA

PBS, 8 p.m. ET

(Check local listings)

This series concludes with, among other things, a very personal touch: Dayton Duncan, who wrote this documentary series and, with Ken Burns, co-produced it, pulls out copies of his own home movies to show exactly when and why he was entranced by the whole idea of national parks. It makes the point beautifully – as does this entire series.