On November 11, 1918, the armistice ending World War I went into effect. The following year on November 11, President Wilson ordered the day as a commemoration of Armistice Day, and essentially Veteran’s Day was born. Veteran’s Day, which is always celebrated on November 11, falls on a Friday this year. Here’s what’s happening .

Fee Free Day, National Parks, Forests and Wildlife Refuges nationwide. The National Park Service offers free admission today. FREE. nps.gov/findapark/feefreeparks.htm.

A Sailor’s Life & Legacy, 9am – 6pm, USS Constitution Museum, Charlestown Navy Yard, Charlestown. Learn about the daily struggles on board “Old Ironsides” during the War of 1812. Through Nov. 13. By donation; veterans free. 617-426-1812; ussconstitutionmuseum.org.

Rockets’ Red Glare, 10am – 4pm, The Children’s Museum in Easton, 9 Sullivan Ave., Easton. Build different types of rockets and then launch them. Free with admission. 508-230-3789; childrensmuseumineaston.org.

Veterans Day Bootcamp Challenge, 9am – 4pm, Rocky Woods, Medfield. Prove your toughness on a self-guided hike with physical and mental challenges like pull ups and puzzles. FREE. 978-356-4351; ttor.org.

Veterans Day, 9:30am – 5pm, Old Sturbridge Village, 1 Old Sturbridge Village Road, Sturbridge. Celebrate the nation’s military history – see musket balls cast, drill with the Village militia and more. Free with admission; veterans free. 800-733-1830; osv.org.

Veterans Day, 11am – 3pm, Spellman Museum, 241 Wellesley St., Weston. Write and send letters to our troops, take part in stamp hunts and stamp crafts. Free with admission. 617-784-5838; spellman.org.