Though they might seem like just another visitor attraction at a winery, wine caves do serve a specific purpose — to store wine at a steady, cool temperature as it ages to perfection. And when it’s hot outside, these underground caverns also do a great job of keeping wine tasters comfortably chilled.
Here are a few favorite carved-out hillsides where you can taste wine and stay cool in the hot days ahead.
Gundlach Bundschu Winery
At Sonoma County’s second oldest family-owned winery, six generations of the Bundschu family have been busy making wine since 1858. The Underground Cave Tour is offered at 11 a.m. and 2:30 p.m. daily. Tour hosts guide guests through the wine cave — as well as the regenerative vineyards, weather permitting — while teaching them about Gundlach Bundschu’s family history, its winemaking and barrel-aging process, and sustainable vineyard practices. Tours last about 90 minutes. Limited to guests 13 and over. Reservations are required; reserve on Tock. $80 per person. 2000 Denmark St., Sonoma, 707-938-5277, gunbun.com


Buena Vista Winery
Founded in 1857 as California’s first premium winery, Buena Vista is listed on the National Register of Historic Places. During the Barrel Tasting and Winery Tour, guests learn about the founder of the historic winery, Count Agoston Haraszthy, and try a flight of wines, including a barrel tasting in the cave. The tour is offered at 11 a.m. and 2 p.m. daily and lasts 90 minutes. $60 per person, $48 for wine club members. Reserve on Tock. 18000 Old Winery Road, Sonoma, 800-926-1266, buenavistawinery.com
Benziger Family Winery
Private wine tastings and dinners in the caves are available at Benziger Family Winery. The Tribute Estate Tour & Tasting includes a visit to the caves. Tours run approximately 90 minutes and are offered at 10 a.m., 11:30 a.m., 1 p.m. and 2:30 p.m. Thursday through Monday; and at 10:30 a.m. and 2:30 p.m. on Sunday. Reservations are required and tours are limited to guests 21 and over. $85 per person, $68 for wine club members. 1883 London Ranch Road, Glen Ellen, 707-935-3000, benziger.com


Bella Vineyards & Wine Caves
Bella’s Immersive Winery Tour starts next to the winery’s 100-year-old Zinfandel vines, but a majority of the time is spent underground in the wine caves. The experience ends with a seated private tasting of five wines, including small-lot Zinfandels. Allow up to two hours for the tour. $95 per person, 15% off for wine club members. Reserve on Tock. 9711 West Dry Creek Road, Healdsburg, 707-473-9171, bellawinery.com
Alexander Valley Vineyards
Complimentary cave tours are offered at noon and 2:30 p.m. daily. While exploring the 48,000-square-foot wine cave, guests learn about barrel selection and how it can impact a wine’s flavor. Reservations are required for groups of seven or more. Tours last about 20 minutes. The winery also offers an Immersive Cave Tour & Tasting Experience at 1 p.m. Saturday and Sunday. Guests will learn about the history of Cyrus Alexander, the valley’s namesake, as well as the Wetzel family, who helped shape the region’s winemaking. While exploring the cave, guests will have a chance to taste five estate wines. Tours are 90 minutes and are not available in September and October. Reserve all experiences on Tock. $45 per person. 8644 Highway 128, Healdsburg, 707-433-7209, avvwine.com


Thomas George Estates
This wine cave, completed in 2010, measures over 8,000 square feet, with nearly 2,000 square feet dedicated to hosting visitors. Guests can explore the entire cave, from production spaces with barrels and concrete vessels to the Wine Cave Library. The Single Vineyard Cave Tasting includes a seated tasting in the wine cave, tasting of six wines and a pizza for two. $75 per person, $90 per person for groups of nine or more. Reservations are recommended. 8075 Westside Road, Healdsburg, 707-431-8031, thomasgeorgeestates.com
Deerfield Ranch Winery
Guests can tour this 23,000-square-foot wine cave, shaped like a wine glass, during cave tastings held daily (by reservation only). The tour lasts about an hour and includes tasting of five wines. Guests learn about the advantages the subterranean space provides for aging wine and how extended barrel aging impacts the wine. $35 per person for the Signature Tasting in the cave, $75 per person for the Reserve Tasting. Reserve on Tock. 10200 Sonoma Highway, Kenwood, 707-833-5215, deerfieldranch.com


Schug Carneros Estate Winery
During the Estate Cave Experience, guides welcome guests with a glass of sparkling wine then lead them on a stroll through the cave. The tour culminates in an intimate seated tasting. The tour lasts about 90 minutes. $65 per person. Reserve online. 602 Bonneau Road, Sonoma, 707-939-9363, schugwinery.com
Kunde Family Winery
Offered November through March, the Cave Tasting at Kunde includes a tasting of the estate’s library and reserve wines along with cheese and charcuterie bites while seated in Kunde’s hillside caves. Available at noon and 3 p.m. Thursday through Monday. Allow two hours for the experience. Reservations are required. $100 per person; exclusive discount price for wine club members. 9825 Sonoma Highway, Kenwood, 707-833-5501, kunde.com

Hamel Family Wines
During Hamel’s Estate Experience, guests are led on a guided tour of the winery and adjacent wine cave while learning about the estate’s volcanic terroir and biodynamic farming philosophy. The tour includes a seated tasting of single-vineyard Sauvignon Blanc, library Cabernet Sauvignon and other estate reds, along with a seasonal snack. Allow up to two hours for the experience. $95 per guest. Maximum six guests per party. Reserve on Tock. 15401 Sonoma Highway, Sonoma, 707-996-5800, hamelfamilywines.com