Occurrence of Attributes in Original Text
The text related to the cultural heritage 'Ha Long Bay' has mentioned 'Sea level' in the following places:
| Occurrence Sentence | Text Source |
|---|---|
| During the Carboniferous and Permian periods (340-250 million years ago), Ha Long Bay was at shallow sea level. | WIKI |
| Many of these at sea level extend right though the limestone hills into drowned dolines which are now tidal lakes. | WIKI |
| Some marine notch caves had been not formed at present sea level, but old sea levels related to sea level changes in Holocene transgression, event to Pleistocene sea levels. | WIKI |