Created by the interaction of water, calcium bicarbonate and limestone, the distinctive cave formations of stalagmites and stalactites are often mistaken for each other. Stalagmites grow upwards from the floor of a cave, formed by drips of water saturated with calcium bicarbonate. Stalactites, made of a similar deposit of crystalline calcium bicarbonate, grow downwards, like icicles. Both are formed by water and calcium bicarbonate filtering through limestone and partially dissolving it. In limestone caves, stalagmites and stalactites are usually white (from the limestone) or brown; in caves where copper deposits are present colours might be more psychedelic, with iridescent greens and blues. They often become united, over time, in a single column.

Travel offers; book through Rough Guides

Costa Rica features

The latest articles, galleries, quizzes and videos.

9 tips for travelling in Costa Rica

9 tips for travelling in Costa Rica

Inspired by pictures of Costa Rica’s primordial-looking shores, rainforests bristling with exotic creatures and steaming volcanoes that tower above the clouds…

25 Oct 2016 • Chloe Cann insert_drive_file Article
14 magical sunrises that prove it's worth getting up early

14 magical sunrises that prove it's worth getting up early

Looking through the Rough Guides photography archive, one kind of shot stands out again and again: pictures captured at sunrise. Sure, there's nothing more temp…

16 Apr 2015 • Eleanor Aldridge insert_drive_file Article
A Rough Guide to spotting wildlife in Costa Rica

A Rough Guide to spotting wildlife in Costa Rica

From world-famous national parks to little-known private reserves, Alex Robinson picks out six of the best places for wildlife-spotting in Costa Rica. Few cou…

19 Jan 2015 • Alex Robinson insert_drive_file Article
View more featureschevron_right

Join over 60,000 subscribers and get travel tips, competitions and more every month

Join over 60,000 subscribers and get travel tips, competitions and more every month