Forty percent of us trace our heritage to the immigrants who arrived through Ellis Island in New York Harbor. You'll pay a ferry charge to get there ($12; $10 for seniors; $5 for kids) but no fee to visit the Statue of Liberty or Ellis Island. At the American Family Immigration History Center, $5 lets you search the ships' records to discover when your ancestors arrived on these shores.
10. Campus Visit - Cambridge, Massachusetts
If you hit the Boston area on a Sunday, you can hear Reverend Professor Peter Gomes, known for his mellifluous voice, dry humor, and ecumenical sermons, preach at Harvard's Memorial Church. Nearby is Annenberg Hall, the freshman dining facility modeled after the great halls at Oxford and Cambridge. Henry James referred to this building as a "house of honor and hospitality." Contemporary visitors who peek through the doorway at the soaring ceilings and stained-glass windows will simply think, Hogwarts.
11. Bridge Crossing - Lexington and Concord, Massachusetts
The confrontation here between the minutemen and the British launched the Revolutionary War. On any July or August day, you can visit Concord's old North Bridge free of charge, cross the river where the Americans made their stand, and see Ralph Waldo Emerson's words etched in stone: "By the rude bridge that arched the flood,/Their flag to April's breeze unfurled,/ Here once the embattled farmers stood,/And fired the shot heard round the world."
12. Natural Wonder - Niagara Falls, New York
This phenomenon on New York's Canadian border has beguiled human beings for centuries. Native Americans called it Thundering Waters and believed its roaring sound emanated from the spiritual world. Legend claims they sent a maiden over the falls in a canoe. Since then, generations of daredevils have tested its power. Gaze from Prospect Point in Niagara Falls State Park. Admission is free, although parking costs $8.
13. Time Travel - Millersburg and Berlin, Ohio
In Amish Country, you can experience the past and future simultaneously: Sit in a coffee shop with free wireless access while watching a Mennonite or Amish family tie horses to a hitching post. Picnic in a field and see the hot-air balloons soar overhead, or attend the Amish Flea Market on Saturdays from April through December.
14. Urban Enjoyment - Chicago
A self-guided tour of this city's architecture, a bike ride along Lake Michigan, and tickets to The Oprah Winfrey Show-requested a year in advance-cost nothing. Thursday evenings, the Art Institute of Chicago and the Chicago Children's Museum waive their fees; the Museum of Contemporary Art is free on Tuesdays. There's never a charge for entry to the National Museum of Mexican Art or for the hourly water and light shows at Buckingham Fountain.
15. Cycling Spectacle - LeClaire, Iowa
Cheer on cyclists doing the RAGBRAI. The what? RAGBRAI (the Register's Annual Great Bicycle Ride Across Iowa) is a seven-day bike ride-not a race-that started 35 years ago as a challenge between two friends at the Des Moines Register. It costs $125 to ride but nothing to applaud the thousands of riders on the last day (this year, July 26) amid a giant party along the Mississippi River in LeClaire.
16. Mountain Picnic - Boulder, Colorado