The Phong Nha-Ke Bang Nation­al Park, inscribed on the World Her­itage List in 2003, cov­ered 85,754 hectares. With this exten­sion, the site cov­ers a total sur­face area of 123,326 hectares (a 46 % increase) and shares a bound­ary with the Hin Nam­no Nature Reserve in the Peo­ples Demo­c­ra­t­ic Repub­lic of Laos. The Park‘s land­scape is formed by lime­stone plateaux and trop­i­cal forests. It fea­tures great geo­log­i­cal diver­si­ty and offers spec­tac­u­lar phe­nom­e­na, includ­ing a large num­ber of caves and under­ground rivers. The site har­bours a high lev­el of bio­di­ver­si­ty and many endem­ic species. The exten­sion ensures a more coher­ent ecosys­tem while pro­vid­ing addi­tion­al pro­tec­tion to the catch­ment areas that are of vital impor­tance for the integri­ty of lime­stone land­scapes.