A Grotto is an internal organization of the National Speleological Society (NSS). They generally function as the local NSS chapter/club. Many Grottos however, operate in areas outside of their local area, with many operating in several states. Most Grottos also participate in Regions which are loose associations of Grottos. Regions are also an internal organization of the National Speleological Society.
Grottos are required to meet certain organizational requirements as outlined by the National Speleological Society. These include:
An annual report describing various aspects of the Grotto is submitted to the NSS.
The New England Grotto was the first NSS Grotto. It was chartered in 1941 with Clay Perry as president and Ned Anderson as vice-president.
Below are the Grottos of the NSS as listed in 2009.