Just beyond the zoo's northeast border is a lovely botanical garden housed in a soaring glass-domed structure. Inside are four great halls filled with thousands of plants. If you're visiting Chicago in the wintertime, I can't think of a better prescription for mood elevation than the conservatory's lush haven of greenery. The Palm House features giant palms and rubber trees (including a 50-ft. fiddle leaf rubber tree dating from 1891), the Fernery nurtures plants that grow close to the forest floor, and the Tropical House is a shiny symphony of flowering trees, vines, and bamboo. The fourth environment is the Show House, where seasonal flower shows are held.

Even better than the plants inside, however, might be what lies outside the front doors. The expansive lawn with its French garden and lovely fountain on the conservatory's south side is one of the best places in town for an informal picnic (especially nice if you're visiting the zoo and want to avoid the congestion at its food concession venues).

The Lincoln Park Conservatory has a sister facility on the city's West Side, in Garfield Park, that is much more remarkable. In fact, the 2-acre Garfield Park Conservatory, 300 N. Central Park Ave. (tel. 312/746-5100), designed by the great landscape architect Jens Jensen in 1907, is one of the largest gardens under glass in the world. It's open 365 days a year from 9am to 5pm. Unfortunately, a rather blighted neighborhood with a high crime rate surrounds the conservatory. If you want to see it, I advise driving there and forgoing public transportation.

Allow a half-hour for the Lincoln Park Conservatory.