The Crystal Grottoes in Boonsboro, Maryland is the only open cave in Maryland and the largest in the state with nearly a half mile of passages. Discovered in 1920, drills penetrated the passages and an opening to the caves was created through a blast. In 1922, after those in charge had installed electrical equipment and cleared the area, the caverns were opened to the public. In 1942, the original wooden opening was replaced by a modern store structure. In many ways, the entrance appears to be a storefront.
Visitors enter the grotto by a stairway in the entrance house. The first cave is eight feet below the house and is shaped in an oblate form, which is 30 feet long, 10 feet wide, and 15 feet high. Originally, this room was filled with a number of formations, but the clearing of the passage removed a number of them. The entrance room connects to the rest of the cave via a 6 foot high tunnel. Once inside, the formations are unique and beautiful and spread throughout the entire cave. Stalactites are the predominate feature in the caves. The color is often white or buff, and they occasionally have deeper tints of color. The area known as Fairyland is covered with stalactites and stalagmites that are slight blue in color.
The area called Blanket Room is the largest area in the cavern and is 30 feet by 20 feet. There are clusters of stalactites in this room that are 20 feet high. Other portions of the cavern are filled with various sizes and varieties of formations. Most of the walls are brown in color and have a nodular texture. You exit the cave through a 40 foot passage way that has a gentle incline toward the outdoors. There are several passages that are not open to the public. The tour includes information about these inaccessible caves, but visitors are not permitted to enter them. The portion of the tour shared with the public is approximately a third of the known cave area.
The Grottoes are located one hour from Baltimore and Washington. One and a half miles outside of Boonsboro, the caves are located in the Frederick Valley area of the state, and the drive there takes visitors through the South Mountain countryside. Nearby are Antietam Battlefield and Harper's Ferry, West Virginia. Guests are invited to bring a picnic lunch to the site of the caves and enjoy the lovely surrounding areas. There are not many dining options close by, but a few fast food restaurants are within a few miles, and there are a number of restaurants, retail stores, and entertainment options a few minutes west in Hagerstown.
The caves are open daily April through October, and Saturday and Sunday November through the end of March. Discounted group rates are available for those that want to plan a multi-person expedition out to the caves. The Crystal Grottoes are a unique, natural attraction that will amaze and educate both children and adults.