Earth Treks' Climbing Centers are state-of-the-art indoor climbing gyms located in Columbia, Timonium and Rockville, MD. We pride ourselves on offering the best rock climbing in the greater Washington DC, Northern Virginia and Maryland region. Each climbing gym is among the largest in the country, with plenty of climbing for every ability level. We make It easy to learn to climb. Each year we teach over 20,000 people to climb.