Consider this an invitation to see, do and explore such wonders as Coltsville National Park (yes), the Bushnell Carousel, printmaking, Legos – oh, and the stellar museums and art centers of Hartford offer free admission for this open house of an event – Envisionfest 2016 – Saturday, Sept. 17.

Let's repeat: Free admission to the Bushnell Center for the Performing Arts, the Connecticut Science Center, Connecticut’s Old State House and the Wadsworth Atheneum – plus more than 100 events throughout the city.

Art, theater, music, walking, biking, history, tours.

EnvisionFest Hartford debuted in 2012 as Connecticut’s Capital City Festival with free activities and performances to showcase Hartford’s abundance of history, arts, extraordinary cultural wealth and a tradition of innovation.

Envisionfest Hartford was created by the iQuilt Partnership, a nonprofit organization whose members include The Bushnell Center for the Performing Arts, the Greater Hartford Arts Council, the MetroHartford Alliance, the Metropolitan District Commission, the Hartford Business Improvement District, Riverfront Recapture and the Capital Region Development Authority as well as the City of Hartford and the State of Connecticut. The iQuilt Partnership is overseen by The iQuilt Plan, a culture-based urban design plan for Downtown Hartford.

The “unusually compact historic district is packed with more than 45 cultural assets and destinations within a 15-minute walk: museums, performance spaces, historic landmarks, modern architecture, and public art. The iQuilt Plan links those assets with a vibrant and innovative pedestrian network. Its centerpiece is the GreenWalk, a one-mile chain of parks and plazas connecting the gold-domed Capitol in Bushnell Park to the waterfront of the Connecticut River.” The iQuilt Plan also produces Winterfest Hartford – the free skating rink that draws throngs of happy ice skaters in Bushnell Park is part of that.

Tobacco Valley Flywheelers Fall Show, Saturday, Sept. 17 and Sunday, Sept. 18, Haddam Meadows State Park. Free. Tractor parades. Antique engines and other agricultural equipment on display and in operation with knowledgeable people to explain how they were used and why. Farm tractors, trucks; working demonstrations. Hay rides. Free activities and contests for the small fry (this is a family-friendly event), plus good food on site for purchase. The flea market area features many interesting items for sale.

The purpose of the Tobacco Valley Flywheelers Gas & Steam Engine Club is to “stimulate interest in collecting, preserving, and exhibiting gasoline, oil, and steam engines, gas and steam tractors, power driven farm machinery, and equipment of historical value.”

Shelburne Farms Harvest Festival, Saturday, Sept. 17, 10 a.m. to 4 p.m., Vermont. Hands-on activities for children, traditional craft demonstrations, exhibits about agricultural, environmental, and energy. Learn about farm machinery, birds of prey, farm animals. Meet rug hookers, woodworkers, weavers, spinners, cheese makers, and gardeners. Demonstrations of wood turning, carving, pole lathe. Hay bale maze and horse-drawn hay rides. Admission, $10; ages 2 and younger, free.

Shelburne Farms is a nonprofit organization with a mission to educate people for a sustainable future. That means learning that links knowledge, inquiry, and action to help students build a healthy future for their communities and the planet. The home campus is a 1,400-acre working farm, forest, and National Historic Landmark. The welcome center – where visitors start for information, maps to trails and tickets – was originally the North Gatehouse for the agricultural estate of W. Seward and Lila Webb. It now also serves as a farm store.

There are more than 10 miles of walking trails open year-round, weather permitting, starting from the Welcome Center (check in required). To mid-October access to trails is included in general admission. Note: Leashed dogs are permitted Nov. 1 to March 31; no dogs permitted April 1 to Oct. 31.