A joint investigation by the Russian exile investigative media Dossier Center, the independent Danish media Danwatch, and the British newspaper The Times has uncovered a large construction project in the Ural Mountains, where Russia is reportedly reinforcing a strategic nuclear facility. The site, located deep within the Kosvinski mountain in the Sverdlovsk oblast, is known by the designation "Complex 1335" and the codename "Grot." The facility includes underground spaces, radio centers, communication installations, and systems to support life in enclosed environments. The investigation combined data from public tenders, military documents, satellite images, online photos, and testimonies from former soldiers to piece together the scope of the project. Danwatch claims to have analyzed nearly 2.5 million military tenders and identified thousands of orders related to Complex 1335 between 2018 and 2024. This effort revealed the scale of construction materials being used at the site. According to the findings, the project has involved at least 22,000 tons of steel, which is three times the weight of the Eiffel Tower. In addition, more than 56,000 tons of cement and approximately 600 kilometers of unspecified materials have been ordered. These figures suggest a massive infrastructure build-up, likely aimed at enhancing Russia's military and nuclear capabilities in the region. The investigation highlights the growing interest in Russia's military infrastructure, especially in areas that are geographically and strategically significant. The Ural Mountains have long been considered a key location for military and industrial projects due to their central position within Russia and their natural barriers. The details of this project have raised questions about Russia's long-term defense strategies and the potential implications for international security.