ALGHERO, ITALY'S NEPTUNE'S GROTTO Neptune's Grotto, located in the stunning Sardinia region of Italy, is well-known for its stalactites, which are mineral deposits.

THE CAVES AT PHANG NGA BAY, PHUKET, THAILAND Beautiful sea caves may be seen in Phuket's Phang Nga Bay.

MEXICO's CENOTE DOS OJOS, TULUM Cenote Dos Ojos, a pair of sea caverns, was formed by two 70-foot sinkholes.

Portuguese cave BENAGIL Portugal's Benagil is a charming little fishing community. A beautiful cave is located in the coastal community, which is accessible by boat.

Portuguese cave BENAGIL Portugal's Benagil is a charming little fishing community. A beautiful cave is located in the coastal community, which is accessible by boat.

GRACE'S BLUE CAVES, ZAKYNTHOS A number of breathtaking blue caves may be seen below Cape Skinari's cliffs. The Kianoun Cave is the biggest here.