Arche Nebra (Nebra Ark) is a visitor center and observation tower designed around a 3,600-year-old bronze sky disc. Discovered in 1999, the disc depicts complex astronomical phenomena and quickly became the heart of an architecture competition. The winning design by Holzer Kobler Architekturen is located in Wangen, Saxony-Anhalt, Germany and symbolizes a solar barge. Covered in yellow anodized aluminum, the 60-meter-long body of the building appears to float above the glass-encased entry. A permanent exhibition explores the site of the discovery and its history. Two separate panoramic windows frame views of the Mittelberg mountain and the Unstrut river.
The precise site where the disc was found is marked by a 30-meter-high tower with a vertical crevice that lines up with the summer solstice. Once each day the sun passes through the opening, indicating the line of sight to the Brocken mountain 80 kilometers away.