Stalactite in the context of "Stalagmite"

43°12′16″N 23°29′28″E / 43.20444°N 23.49111°E / 43.20444; 23.49111

Ledenika (Bulgarian: Леденика, English: icy or glacial) is a cave in the Northwestern parts of the Balkan Mountains, 16 km away from the Bulgarian city of Vratsa. Its entrance is approximately 830 m above sea level. The cave features an abundance of galleries and impressive karst formations including stalactites and stalagmites. It was first discovered around the beginning of the 20th century and has been open to tourists since 1961. Ledenika Peak on Graham Land in Antarctica is named after the cave, in recognition of its cultural importance.

The Bacho Kiro cave (Bulgarian: пещера "Бачо Киро") is situated 5 km (3.1 mi) west of the town Dryanovo, Bulgaria, only 300 m (980 ft) away from the Dryanovo Monastery. It is embedded in the canyons of the Andaka and Dryanovo River. It was opened in 1890 and the first recreational visitors entered the cave in 1938, two years before it was renamed in honor of Bulgarian National Revival leader, teacher and revolutionary Bacho Kiro. The cave is a four-storey labyrinth of galleries and corridors with a total length of 3,600 m (11,800 ft), 700 m (2,300 ft) of which are maintained for public access and equipped with electrical lights since 1964. An underground river has over time carved out the many galleries that contain countless stalactone, stalactite, and stalagmite speleothem formations of great beauty. Galleries and caverns of a 1,200 m (3,900 ft) long section have been musingly named as a popular description of this fairy-tale underground world. The formations succession: Bacho Kiro's Throne, The Dwarfs, The Sleeping Princess, The Throne Hall, The Reception Hall, The Haidouti Meeting-Ground, The Fountain and the Sacrificial Altar.

A speleothem (/ˈspiːliəθɛm/; from Ancient Greek σπήλαιον (spḗlaion) 'cave' and θέμα (théma) 'deposit') is a geological formation made by mineral deposits that accumulate over time in natural caves. They can take a variety of forms, depending on their depositional history and environment. Common forms include stalagmites, stalactites, and flowstones.

Speleothems most commonly form in calcareous caves due to carbonate dissolution reactions. Their chemical composition, gradual growth, and preservation in caves make them useful paleoclimatic proxies.

Travertine (/ˈtrævərtiːn/ TRAV-ər-teen) is a form of fresh water limestone deposited around mineral springs, especially hot springs. It often has a fibrous or concentric appearance and exists in white, tan, cream-colored, and rusty varieties. It is formed by a process of rapid precipitation of calcium carbonate, often at the mouth of a hot spring or in a limestone cave. In the latter, it can form stalactites, stalagmites, and other speleothems.

Travertine is frequently used in Italy and elsewhere as a building material. Similar, but softer and extremely porous deposits formed from ambient-temperature water are known as tufa.

Fiorite is a hydrated silica mineraloid, a form of opal, found in cavities in volcanic tuff. It is a globular, botryoidal, or stalactic concretionary form of opal. The mineraloid has a pearly lustre and forms botryoidal masses. Named after Santa Fiora, Italy, fiorite is used as a gemstone.

A lava tube, more rarely called a pyroduct, is a 'roofed conduit through which molten lava travels away from its vent'. If lava in the tube drains out, it will leave an empty cave. Lava tubes are common in low-viscosity volcanic systems. Lava tubes are important as they are able to transport molten lava much further away from the eruptive vent than lava channels. A tube-forming lava flow can emplace on longer distance due to the presence of a solid crust protecting the molten lava from atmospheric cooling. Lava tubes are often considered when preparing hazard maps or managing an eruptive crisis.