The town itself deserves a look before you head for the bodegas. The Old Quarter is filled with mansions, some from the 16th century; the most interesting ones lie along Calleja del Castillo. At the center of the Old Quarter is the town's major architectural landmark, Iglesia de Santo Tomás, Plaza de la Iglesia. Distinguished by its wedding-cake tower and Plateresque south portal, the 16th-century church has a Gothic interior.
You could spend up to 3 days touring the wineries in town, but chances are that a few visits will satisfy your curiosity. Bodegas Muga, Av. Vizcaya s/n (tel. 94-131-04-98), near the rail station, offers tours (usually in Spanish) of its wine cellars. A tour in English is offered Monday to Friday at 11am. The winery is closed at Easter and August 1 to August 15.
Finally, pay a visit to Rioja Alta, Av. Vizcaya s/n (tel. 94-131-03-46), not far from Muga. It's open Monday to Friday from 10am to 2pm. Visits must be arranged in advance.
If you arrive in Haro in August or the first 2 weeks in September, when many of the bodegas are closed, settle instead for drinking wine in the tascas that line the streets between Parroquia and Plaza de la Paz. After a night spent there, you'll forget all about the bodega tours. Some of the finest wines in Spain are sold at these tascas, along with tapas -- all at bargain prices.
Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.