Holiday Open House from 4 to 8 p.m. Friday at the Longfellow House/Washington’s Headquarters National Historic Site, 105 Brattle St., West Cambridge, and Winter Solstice Farewell to Fall from 2:30 to 4 p.m. Sunday at the Fresh Pond Reservation, 250 Fresh Pond Parkway. Free.

Take advantage of unique historical and natural aspects of the city: On Friday, walk the halls and rooms of the decorated Longfellow home, stroll the illuminated grounds, listen to favorite carols and enjoy refreshments and arts and crafts in the Carriage House; on Sunday, say farewell to fall and welcome winter as a ranger leads a 2.25-mile loop walk around Fresh Pond and discusses its solstice traditions of nature and culture. The walk takes place rain or shine, so dress for the weather and meet at the Fresh Pond Ranger Station. (Look for the door under the clocktower facing the pond; the water treatment plant has a public entrance with restrooms.) Information is here and here.

Cirque Us! at 6 and 8:30 p.m. Friday at The Center for Arts at the Armory, 191 Highland Ave., Somerville. Tickets are $15 in advance through midnight tonight (actually $16.52 with the online service fee) or $20 at the door.

Youth and young adult aerialists, jugglers, acrobats and clowns, made up of alumni and current students from troupes such as Circus Smirkus, the New England Center for Circus Arts, École Nationale de Cirque and École de Cirque de Quebec, perform a family-friendly show of high-level thrills to fund an upcoming summer tour. Information is here.

Beyond Tabletop Game Jam from 6 to 8 p.m. Friday and 10 a.m. to 8 p.m. Saturday at NuVu Studio, 450 Massachusetts Ave., Central Square. Free.

This is the kind of interactive entertainment you probably cannot find outside of Cambridge. Move38, an MIT Media Lab spinoff, invites all to a sneak preview of the screen-free tech it thinks can transform tabletop gaming. This game jam for designers, developers and game enthusiasts allows for a chance to play with Blinks, the smart LED tiles used to play “Mortals” (described as “a game of the future” by the Geek & Sundry website back when the  game was known as “Live Free or Die” and it was played with “AutomaTiles”). There’s a kickoff and intro from 6 to 8 p.m. Friday and a game jam from 10 a.m. to 6 p.m. Saturday, followed by a final play test from 6 to 8 p.m. Saturday. Information is here.

Holiday concerts with brass from 7 to 8 p.m. Saturday at Saint Peter Parish, 100 Concord Ave., West Cambridge; and with strings from 11 a.m. to noon Sunday at the Longy School of Music of Bard College, 27 Garden St., Harvard Square.

Bay Colony Brass, called New England’s preeminent brass ensemble by event organizers, gives a Christmas concert early in the weekend, and more than 100 skilled strings students at Longy – including its Allston, Chinatown and St. Patrick orchestras – close it out with a final holiday concert. Information is here and here.

Frozen Chanukah from 11 a.m. to 1 p.m. Sunday at Community Ice Skating at Kendall Square, 300 Athenaeum St. Admission is $10 per family.

The Cambridge Jewish Center of the Arts’ event returns for a third skate, with latkes and doughnuts, Chanukah crafts and an appearance by Olaf from “Frozen” included. Information is here.