WesternEurope

Spread over an area of approximately 15,000 m2, the Exotic Garden is home to a thousand cacti and other succulent plants with stems or hypertrophic leaves which store water. Originally from the planet’s main semi-arid regions, these plants still produce plenty of flowers. The principal flowering seasons are winter (January–February) for South African succulents such as Aloe and Crassula, and spring and summer for cacti, a family native to the American continent. The enormous trees which line the paths of the Exotic Garden illustrate the age of the collection which served as the basis for the creation of the garden at the instigation of Prince Albert I. Opened to the public in February 1933, and supplemented in the 1960s by a botanical centre and specialist tree nursery, the garden is one of the Principalities most visited tourist attractions. At the base of the cliff on which the Exotic Garden is situated (called “the observatory” due to the long-standing presence of a small astronomical observatory), at an altitude of 100 metres, there is a subterranean chamber equipped to receive visitors. The limestone rock, carved out by water containing carbon dioxide, is studded with caverns adorned with geological formations bearing evocative names: stalactites, stalagmites, draperies, columns, soda straws... Expert guided tours of the cave are included in the entry ticket for the Exotic Garden. The tour travels from a depth of 98 metres to a depth of 40 metres (around 300 steps). The chamber plunges down almost to sea level and is regularly explored by local cavers. The presence of prehistoric humans in the region of the cave is confirmed by the bones of the animals that they ate. These remains also illustrate the climate variations that have taken place over the last 250,000 years. http://www.visitmonaco.com/en/Places-to-visit/Gardens/The-Exotic-Gardens-and-the-Observation-Cave

The underground cavity has the longest horizontal run of the Region of Murcia and its more than 700 meters long. It has different astonishing rooms and spectacular rock formations with three fantastic audiovisual shows. Locution and synchronized lighting with LED technology and exciting walkways all provided. Also specialized guides for excursions. The Cueva del Puerto Reception Centre of Calasparra has a cafeteria, a multipurpose hall also used for conferences, interpretative room, terraces for activities, parking lots, cave tourism centre, etc. https://www.murciaturistica.es/en/monument/cueva-del-puerto-5270/

Take some time away from the heat of the day in the eerie, underground caverns of the Cueva Can Marça in Puerto de San Miguel. Spookily silent and illuminated in strange colours, the formations of stalagmites and stalactites make for a Jurassic backdrop to the tour of the cavernous galleries. Originally used by smugglers to store contraband, the marks they used to guide them in the dead of night can still be seen on the walls. At the heart is a spectacular music and light show with a 10 metre cascade of water. Visitors also get to see the magnificent views out to sea from openings hewn into the cliff side. https://www.ibiza-spotlight.com/activity/can-marca-caves

The world's largest limestone mine. An endless maze of galleries with caves as large as cathedrals and narrow paths where an adult man cannot walk upright. An enormous 60 km labyrinth of passageways with caverns as large as a cathedral, and narrow tunnels where you have to walk doubled up. 2 km of the passageways are lit. A multi-media presentation shows the history of the mines. Exhibitions and films tell about bats, geology and mining. Groups are granted admission all the year round with prior reservation. Guided tours in Danish, English and German can be arranged. https://www.visitviborg.com/viborg/plan-your-trip/monsted-limestone-mines-gdk601327

Mother Shipton’s is a beloved Knaresborough landmark and England’s oldest visitor attraction, open since 1630. This popular visitor attraction tells the story of Mother Shipton and the Petrifying Well. A picturesque mile-long walk along the River Nidd features the cave where famous Yorkshire prophetess Mother Shipton was born. It is situated next to the Petrifying Well, a unique geological phenomenon. Over hundreds of years, curiosity has drawn millions of visitors to the well to see cascading water turn everyday objects to stone - as if by magic. People around the world visit the park, a remnant of the Royal Forest of Knaresborough with some of the oldest, tallest beech trees in the country. Mother Shipton was born in a cave in 1488 and grew up around Knaresborough. As she grew older, her prophecies became known throughout England. She foretold the defeat of the Spanish Armada in 1588 and the Great Fire of London in 1666. She made her living telling the future and warning those who asked of what was to come. Great for all ages, there’s fun for families in the adventure playground, scenic picnic areas, interactive trails and actors during events, and petrified objects displayed in the museum and gift shop. https://www.visityork.org/explore/mother-shiptons-cave-p841711

The limestone of the Picardy plateau was dug out in many places to form refuges. These refugees were called "muches" (hideouts in Picard language). Those in Naours, rediscovered at the end of the last century, are the largest known: all the underground areas combined can house around 2,600 people with their livestock. The layout is remarkable: around 300 chambers, public squares, stables, wells, chimneys, and a chapel with three naves. These underground areas were used by the British forces during the First World War and were used as the headquarters of the German forces during the second world war. Exhibitions of traditional trades. In the park: games, 2 windmills from the 18th century. http://www.visit-amiens.com/tourinsoft/details/en_patrimoineculturel/PCUPIC0800010624/PCU