When we're traveling, my family never passes up a chance to go underground. Jared, age 10, Kyle, 8, and Paisley, 4, are alternately transfixed by the stalactites and stalagmites, awed by the darkness, or sent into fits of giggles by the "bacon" on the ceiling and "popcorn" on the walls. As avid cave fans, we give you our top picks for subterranean sightseeing.1. CALIFORNIA CAVERN, Mountain Ranch, California Wander along the Trail of Lights, then hang out amid the Jungle Room's pristine formations of dangling stalactite vines and soda straws. $14.25 for adults, $7.15 for kids ages 3 to 12; 866-762-2837; California Cavern
2. CARLSBAD CAVERNS NATIONAL PARK, Carlsbad, New Mexico
Explore the awesome Big Room: at more than eight acres in size, it's the largest cave room in the nation. A one-mile self-guided tour takes you past such sights as the Bottomless Pit and the Witch's Finger. Summer visitors can see sunset flights of Mexican free-tailed bats at the cave's entrance. $6 for ages 16 and up; other, ranger-guided tours available for additional fees; 575-785-2232; Carlsbad Caverns
3. JEWEL CAVE NATIONAL MONUMENT, Custer, South Dakota The second-longest cave in the world -- at 142 miles -- offers a scenic half-mile excursion showcasing its famed formations, including flowstone, calcite crystal jewels, cave bacon, and cave popcorn. $8 for adults, $4 for kids ages 6 to 16; other tours available for additional fees; 605-673-2288; Jewel Cave
4. CAVERNS OF SONORA, Sonora, Texas Many of the colorful formations on this 1 3/4-mile tour resemble familiar objects, such as a white rat, a quarterback throwing a football, a carrot, and a butterfly. $20 for adults, $16 for kids ages 4 to 11; 325-387-3105; Caverns of Sonora
5. NIAGARA CAVE, Harmony, Minnesota A 60-foot waterfall is one of the star attractions at this cave, along with fossils, stalactites, and stalagmites. It's open May to September, and weekends in April and October. $10.50 for adults, $9 for kids ages 13 to 17, $6 for kids ages 4 to 12; 800-837-6606; Niagara Cave
6. MERAMEC CAVERNS, Stanton, Missouri Tours of this multilevel cavern are accompanied by lighting effects and music and include a visit to the 70-foot-tall Stage Curtain, the largest cave formation in the world. $17.50 for adults, $8 for kids ages 5 to 11; 800-676-6105; Meramec Caverns
7. MAMMOTH CAVE NATIONAL PARK, Mammoth Cave, Kentucky With 85 miles of trails topside and multiple tours underground throughout the year, this national park has enough to keep your family busy for a week. See the Great Wall of China or take the two-mile Historic Tour, which captivates kids with intriguing features, such as the narrow passageway dubbed Fat Man's Misery. $12 for adults, $8 for kids ages 6 to 12; other tours available for additional fees; 270-758-2180; Mammoth Cave
8. HOWE CAVERNS, Howes Cave, New York To tour this popular cave, you first navigate the Winding Way on foot, then embark on an underground boat ride across the Lake of Venus. $18 for adults, $15 for kids ages 12 to 15, $10 for kids ages 5 to 11; 518-296-8900; Howe Caverns
9. LURAY CAVERNS, Luray, Virginia Although there are plenty of interesting formations in this large cave, the indisputable highlight is its unique Stalacpipe Organ (pictured). It really plays music! $19 for adults, $9 for kids ages 6 to 12; 540-743-6551; Luray Caverns
10. FLORIDA CAVERNS STATE PARK, Marianna, Florida While exploring these family-friendly Sunshine State chambers, you'll get close-up views of dazzling stone draperies and ribbon formations. $4 per vehicle, plus $8 for adults, $5 for kids ages 3 to 12; 850-482-1228; Florida Caverns State Park



