Gold, the enduring safe investment and symbol of wealth, comes at a high price. Mined in slave-like conditions, it has been linked to everything from funding civil wars in Africa to causing environmental disasters in Latin America. The market for gold is enormous with 70% of global production handled by just one country: Switzerland. The industry has been protected by the Swiss state for more than a century, and turning a blind eye here is standard practice. Despite attempts at reforms, a lack of transparency still remains. We travel to Peru, Congo, Dubai and Switzerland to investigate.