This premium service, available outside regular opening hours, accommodates up to four groups of five people each, with a cost of €5,000 per group, although individuals willing to cover the full group fee may book a tour on their own.

Credits: Getty Images; Author: George Pachantouris;

The Cultural Resources Management and Development Organisation reports that the tours have attracted clients primarily from European countries, including groups, families, couples and, in one case, a solo visitor.