| 1 | A | B | C | D | E |
| --- | --- | --- | --- | --- | --- |
| 2 | List of longest caves - List |  |  |  |  |
| 3 | System | Length | Location | Discovery | Associated parks, protected areas |
| 4 | Mammoth Cave | 651.8 km (405.0 mi) | near Brownsville, Kentucky, United States | 1791 | Mammoth Cave National Park, also a World Heritage Site and International Biosphere Reserve |
| 5 | Sistema Sac Actun / Sistema Dos Ojos | 360.5 km (224.0 mi) | near Tulum, Quintana Roo, Mexico | 1987 | none |
| 6 | Jewel Cave | 324.9 km (201.9 mi) | near Custer, South Dakota, United States | 1900 | Jewel Cave National Monument |
| 7 | Sistema Ox Bel Ha | 270.2 km (167.9 mi) | near Tulum, Quintana Roo, Mexico | 1996 | southern parts in Sian Ka'an Biosphere Reserve |
| 8 | Shuanghedong Cave Network | 257.4 km (159.9 mi) | Guizhou, China | 1988 | Suiyang Shuanghedong National Geopark |
| 9 | Optymistychna Cave | 257.0 km (159.7 mi) | near Korolivka, Ukraine | 1966 | Dnistrovskyy Canion |
| 10 | Wind Cave | 241.6 km (150.1 mi) | near Hot Springs, South Dakota, United States | 1881 | Wind Cave National Park |
| 11 | Clearwater Cave System | 227 km (141.1 mi) | near Miri, Sarawak, Malaysia | 1978 | Gunung Mulu National Park, also a World Heritage Site |
| 12 | Lechuguilla Cave | 222.6 km (138.3 mi) | near Carlsbad, New Mexico, United States | 1900 | Carlsbad Caverns National Park |
| 13 | Fisher Ridge Cave System | 208.8 km (129.7 mi) | near Brownsville, Kentucky, United States | 1981 | partly within Mammoth Cave National Park |
| 14 | Hölloch | 201.9 km (125.5 mi) | Muotathal, Switzerland | 1875 | none |

Question: How long is the Optymistychna Cave compared to other caves in the world?
Answer: Optymistychna Cave is one of the longest cave in the world, after Mammoth Cave, Sistema Sac Actun, Jewel Cave, and Sistema Ox Bel Ha.