Gettysburg National Military Park celebrates a birthday today, its 114th, but it was the battle anniversaries that interested the Civil War veterans. In 1938, the 75th anniversary of the battle, motion picture crews filmed the aged veterans at the battlefield as they gathered for their final reunion. There’s some amazing film footage on the Internet.

Muir Woods National Monument, which celebrates its 101st anniversary today, is swarmed by visitors who admire the giant redwoods but pay little heed to the ecosystem’s lesser publicized features. A profusion of life surrounds those big trees, interacts with them, and participates with them in the intricate processes of energy flow and matter recycling that sustain the ecosystem.

Minidoka National Historic Site, the former Minidoka Internment National Monument, has acquired vital new acreage and a satellite site that will tell the park’s story in a richer, more complete way. Preserving and interpreting a World War II concentration camp for people of Japanese ancestry helps teach important lessons about racial prejudice, injustice, and the loss of civil liberties.

Lava Beds National Monument, which celebrates its 83rd birthday November 21, is a strange looking place bursting with fascinating stories. As if the largest collection of lava tubes and caves in the coterminous states weren’t enough to make this park very special, it’s also where Captain Jack and his warrior band fought an amazing battle against an attacking force ten times its size during the Modoc War of the early 1870s.