sentence1: Take a trip to nearby Conca dei Marini to visit the stalactites of the Grotta di Smeraldo or Emerald Grotto, where the waters are as brilliantly emerald green as those of Capri's Grotta Azzurra are blue, believed by many to be even more beautiful.
sentence2:  Capri's Grotta Azzurra's waters are blue, but they are not as pretty as The Emerald Grotto's.