Always free for city residents, the 55-acre San Francisco Botanical Garden is offering free admission to all (usually $8 for adults and $6 for kids and seniors) on Thanksgiving Day. Before or after the big meal, you're encouraged to bring out-of-town guests for a stroll through thousands of plants from around the world.

Entry to the SFBG is also free on Christmas and New Year's Day, as well as every morning from 7:30-9am and all day on the second Tuesday of each month. The garden opens at 7:30 am; last entry is at 4 pm, and it closes an hour later.