The best tour is through Elisabeth Lajtonyi at Outdoors Chile (tel. 63/212931 or 09/444-3192; www.outdoors-chile.com). She can arrange your entire trip in Valdivia, from reserving hotels to airport transfers and personalized sightseeing tours.
The bustling Mercado Fluvial, at Muelle Schuster (Av. Prat at Maipú), is the principal attraction in Valdivia and is worth a visit for the dozens of fishermen who hawk fresh conger eel, hake, and spindly king crabs in front of colorful fruit and vegetable stands. Take a peek behind the fish stands to view the lanky pelicans and enormous sea lions barking for handouts. Across the street, the Mercado Municipal holds few attractions apart from a couple of souvenir shops and decent, inexpensive restaurants. Hours for the various shops here are erratic, but they are generally open Monday through Sunday from 9am to 7:30pm, closing at 9pm in summer, with some restaurants open later.
A block up from the waterfront, turn right on Yungay and head south until the street changes into General Lagos at San Carlos. A pleasant stroll for several blocks along General Lagos offers picturesque evidence of German immigration to the area through the stately, historic homes that dot the street. The houses, built between 1840 and 1930, belonged to affluent families, and many have been restored and maintained, despite the various earthquakes and other natural disasters that have beset them since construction.
Take a step back in time at the Centro Cultural El Austral, Yungay 733 (tel. 63/213658), commonly known as the Casa Hoffman for the Thater-Hoffman family, who occupied the home from 1870 until 1980. It's open Tuesday through Sunday from 10am to 1pm and 4 to 7pm; admission is free. The first floor of this handsome building has been furnished to re-create the interior as it would have looked during the 19th century, complete with period antiques, paintings, and a few very garish chandeliers. Upstairs, the center holds temporary art exhibitions and painting, literature, and history classes. At the junction of General Lagos and Yerbas Buenas is the Torreón de Los Canelos, a 1781 defensive tower built to protect the southern end of the city -- but if you're strapped for time, forget it.