海穴

Grotto

澳洲海岸線綿長，「海穴」是其中一個地理特徵，當水積聚，並慢慢滲透，最終腐蝕地表，形成大坑，就是「海穴」了。

Australia has a beautiful long coast line. ‘Grotto’ is one of the many geographic features.

1. Water fills a swampy depression.

2. Water seeps through the clay surface to the limestone below.

3. Weak acids begin to dissolve the limestone layers.

4. A sinkhole is formed which, in time, becomes bigger and shapes the Grotto.

Source: Parks VICTORIA