Maya Bay, ringed by cliffs on Ko Phi Phi Ley island and surrounded by azure waters, was made famous when it featured in the 2000 film starring Leonardo Dicaprio.
It was shut last June by Thai authorities due to worries the white-sand paradise was suffering from the pressure of thousands of day-trippers arriving by boat.
Last year officials temporarily closed the beach and now the closure has been extended to give its ecology more time to recover.
Authorities had initially said the beach — a massive draw for Thailand’s more than 38 million tourists — was going to be closed for four months, but the re-opening was repeatedly postponed.
When it eventually reopens, officials plan to restrict the number of visitors and boats will be banned from mooring within the bay’s waters.
Before Maya Bay’s closure, up to 5,000 tourists visited daily, causing trees and smaller vegetation to be uprooted, creeping soil erosion, and severe damage to the corals in the bay.
A majority of the visitors were ferried there from tourist hotspot Krabi province by local longtail boatmen or tour operators who touted the movie-famous bay as a key attraction for day trips.
“Maya Bay is the heart of our tourism,” said Wattana Rerngsamut, chairman of Krabi Provincial Tourism Association which represents some 200 tourism and hotel operators.
Thailand experienced a three-month slowdown in tourism last year, most noticeably since July when a ferry sank and killed 47 Chinese visitors off nearby Phuket.