Grotto

A grotto (Italian grotta and French grotte) is a natural or artificial cave used by humans in both modern times, and historically or prehistorically. Naturally occurring grottoes are often small caves near water that are usually flooded or liable to flood at high tide. Sometimes, artificial grottoes are used as garden features. The Grotta Azzurra at Capri and the grotto at the villa of Tiberius in the Bay of Naples are examples of popular natural seashore grottoes.

Whether in tidal water or high up in hills, grottoes are generally made up of limestone geology, where the acidity of standing water has dissolved the rock matrix' carbonates as it passes through what were originally small fissures. See karst topography, cavern.

The word "grotto" comes from Italian grotta, Vulgar Latin grupta, and Latin crypta, (a crypt). It is also related by a historical accident to the word "grotesque." In the late 15th century, Romans accidentally unearthed Nero's Domus Aurea on the Palatine Hill, a series of rooms, decorated with designs of garlands, slender architectural framework, foliage, and animals. The rooms had sunk underground over time. The Romans who discovered this historical monument found it very strange, a sentiment enhanced by the fact that it was uncovered from an 'underworld' source. This led the Romans to give it the name "grottesche," or grotesque.

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