Mention Phuket and visions of a sun-kissed beach escape immediately come to mind — where days are spent basking in the tropical sun by the Andaman Sea and nights are filled with the colours and vibrancy of Thailand's renowned nightlife. And no matter where you wander, you're never far from an authentic Thai meal. After all, you're in the Unesco City of Gastronomy. But that's not all to this beach paradise. The next time you visit Phuket, venture beyond the beaches and follow our guide to Phuket Old Town for a cultural adventure at this underrated gem. Just a 30-minute ride from Patong Beach and an hour from the airport, the Sino-Portuguese…