Quick—where would you look for the area’s largest indoor rock-climbing gym? In Rockville, of course. Earth Treks Rockville (725 Rockville Pike; 240-283-9942; earthtreksclimbing.com) features 40-foot-high walls and 100-plus climbing routes, making for more than 16,000 square feet of vertical excitement. It also has two teaching areas and a full-service shop.

In Virginia, try SportRock (5308 Eisenhower Ave., Alexandria; 45935 Maries Rd., Sterling; 703-212-7625 for both; sportrock.com). The Alexandria location offers 12,000 square feet of climbing, Sterling 10,000, both on 40-foot walls.

An introductory class costs $35 at Earth Treks, $25 at SportRock. Both offer membership programs and advanced instruction. Daily rates for nonmembers are $16 and $18, respectively.