The Indianapolis Catacombs are approximately 20,000 square feet (1,900 m²) of underground passageways on the northeast corner of Market and Delaware streets in downtown Indianapolis, Indiana.^[1]

The passages and walkways include brick archways and limestone columns that were part of Tomlinson Hall, a building that opened in 1886 and was destroyed by fire in 1958.^[1][2] Tomlinson Hall was a public auditorium located immediately west of the Indianapolis City Market. The catacombs served as a more convenient way to transport and store goods from the above-ground marketplace and contains pits used to store ice.^[2] Indiana Landmarks offers 30-minute tours on various Saturdays during the year.^[3]