You can see amazing limestone structures chiseled with ornate carvings in this can't - miss ancient citadel. (cancuntours.net)
The Champa ruins at My Son, Imperial capital Hue's ancient citadel monument complex and the more recently discovered Hang Son Dong, the world's largest known cave passage, are all within a two - hour radius. (businesstravelerusa.com)
One is Tikal, a park with Mayan ruins and temples that sits in an ancient citadel within the rainforests of northern Guatemala. (cnbc.com)