Keysone Phomvihane's cave

Keysone Phomvihane's wooden house constructed outside his cave after signing of 1973 Paris Peace accords.
The Pathet Lao government in exile directed the resistance struggle from the “Hidden City”. Five caves were selected as the family homes and offices of the key leaders. Natural caves were enlarged, tunnels developed and artificial roofs built to keep out water. Airtight evacuation chambers with manual filter mechanisms to guard against gas attacks were constructed, along with five-feet thick blast walls to cover cave entrances and prevent rockets and guided missiles from entering. Government ministries were set up in caves in far flung locations. Printing presses, a fuel depot and light industry caves were established to support the war effort. A cave hospital complex was built to take care of the injured and dying, and an underground theatre constructed to entertain the population, with visiting theatre troupes from Vietnam. Fidel Castro visited the caves to lend his country's support.