The room where entrepreneurs pitch on the UK television programme Dragon's Den is called the Den.
The title gives the setting a distinctive identity: contestants enter the Den, face the investors and make their request for money in exchange for a share of their company. The setting is deliberately stark, keeping attention on the entrepreneur, the product and the negotiation.
A typical pitch includes an explanation of the business, the amount sought and the percentage of equity offered. The Dragons then ask questions about sales, costs, intellectual property, competition and future growth before deciding whether to make an offer.
“Boardroom” is a plausible alternative because business programmes often use that term, but it is not the programme's canonical name. The show's own language consistently refers to the investment setting as the Den.