The Conservation Centre for Co Loa and Hanoi citadels on January 19 submitted documentation to the United Nations Educational, Scientific Organisation (UNESCO) to apply for the recognisation of the Thang Long Royal Citadel Site as a World Heritage Site.

A draft document on the Thang Long Royal Citadel Site was first presented to UNESCO on September 25, 2008. After receiving a written response from the World Heritage Committee, the Conservation Centre for Co Loa and Hanoi citadels were prompt to finalise the documents and resubmit them.

The set of documents on Thang Long Royal Citadel Site was written in both Vietnamese and English, including 9 sections and 162 pages, along with 8 appendices, a 45-minute film and 84-photo slideshow.

The materials have been directed to the World Heritage Site Committee 4 days before the deadline of January 30, 2009 set by the organising board.