Origami Holiday Tree The American Museum of Natural History's elaborate seasonal exhibit is a months-long effort; volunteers start folding the intricate paper decorations in July, and approximately 800 can be found on the tree come Christmastime. This year, the origami accessories are inspired by the institution's largest treasures—including the massive blue whale in the Milstein Hall of Ocean Life—with pieces that recall dinosaurs, Mars, an elephant and other gigantic objects. American Museum of Natural History, Grand Gallery, Central Park West at 79th St (212-769-5200, amnh.org). Daily 10am--5:45pm; suggested admission $19, seniors and students $14.50, children 2--12 $10.50, children under 2 free. Through Jan 2.
Rockefeller Center Christmas Tree Brave the crowds around midtown to catch a glimpse of this year's massive conifer, a 74-foot-tall Norway spruce that was trucked in from Mifflinville, Pennsylvania. The practice of lighting a tree in Rockefeller Center began 79 years ago, and remains a classic New York spectacle that shouldn't be missed. Rockefeller Plaza, Fifth and Sixth Aves between 49th and 50th Sts (212-632-3975). Daily 5:30am--11:30pm, Sun 25 24hrs, Dec 31 5:30am--9pm; free. Through Jan 7.
Seaport Chorus Tree The 44-foot-tall structure at the center of South Street Seaport is actually a fake tree: The frame is made of structural steel, and is covered in branches and garlands that are adorned with thousands of LED lights. The decoration is also the focal point of a choreographed light show set to holiday music. Pier 17, Fulton St at Front St (212-732-8257, southstreetseaport.com). Daily 24hrs; free. Light show: Mon--Fri, hourly 5--10pm. Through Sat 24.
Peace Tree The children's book Sadako and the Thousand Paper Cranes—which tells the story of an 11-year-old girl with leukemia who dreamed of folding 1,000 of the origami birds—informs the paper custom at the Cathedral Church of St. John the Divine. The Canadian balsam is meant to be a symbol of peace and features contributions from people across the globe (in the past, musicians Judy Collins and Paul Winter have lent their own folded ornaments to the exhibit). 1047 Amsterdam Ave at 112th St (212-316-7490, stjohndivine.org). Daily 7am--6pm; free. Through Dec 31. Dedication: Fri 16 at 11am.
Park Avenue Memorial Trees The 104 balsam firs that line Park Avenue are more than just festive holiday adornments: The topiaries were first lit in 1945 in remembrance of those who lost their lives during World War II. The tradition continues to this day, and each tree is strung with 25 strands of white lights. Park Ave between 54th and 96th Sts (212-705-4237, fundforparkavenue.org). Daily 5pm--midnight; free. Through Jan 16.