A hidden gem in the city of Alliance, unknown even to many Ohioans, the Troll Hole has one of the world’s largest collections of trolls. Nearly 3,000 unique dolls line the walls, including rarities such as ninja trolls, a three-headed troll, and a vintage Trollmobile.

The Troll Hole Museum was founded in 2014 by Sherry Groom, who began collecting trolls at the age of five. Over the years, Groom grew her collection troll by troll. The mission was not just to snatch the Guinness record for the wold’s largest troll collection (though she did in 2012), but to amuse and educate children about the fascinating backstory of trolls.

Trolls, the toy, were invented in 1959 by Danish Woodworker Thomas Dam and became a huge international craze in the ’60s and again in the ’90s. The toys were designed based on the ugly, mountain-dwelling creatures first mentioned in Scandinavian and Norwegian mythology back in the 13th century—a history Groom will explain in much detail on her tours (occasionally dressed as “Sigrid the Troll Queen”).

The landscape of the Troll Hole Museum is surprisingly elaborate, consisting of a grotto, two waterfalls, a 10-foot troll mountain and troll bridge, and several rooms with different themes. Scattered throughout these features are thousands of miniature trolls and troll-related items, and rows upon rows of figurines with their trademark colorful wild hair.