Brooklyn, like any bustling urban center, is (and has always been) home to a diverse variety of venues constructed and operated with the express purpose of entertainment: from theatres to pools to baseball fields.
In the late 19th and early 20th century, vaudeville theatres were constructed in the most populous areas of Brooklyn, bringing popular entertainment to the working-class masses. In the early decades of the 20th century, the changes in technology altered the way Brooklynites were entertained. Vaudeville waned in popularity as moving pictures were introduced. Some of the early theatres evolved with the times, adding a movie screen and changing their operations, others closed and were razed in the boom of the building that overtook the borough in the first half of the 20th century. This massive development growth meant the former sleepy rural areas of south Brooklyn were becoming vibrant communities. New movie theatres, often designed by well-known architects, popped up everywhere, offering cheap entertainment (and snacks!) to generations of first dates and family outings.
As technology once again evolved in the second half of the 20th century and television allowed for similar entertainment within one's home, theatres suffered. In the financially depressed years of the 1970s, many movie theatres closed or transitioned to more "adult" entertainment. Very few of Brooklyn's early 20th century venues remain operating movie theatres today. Those structures—not an inconsiderable number, particularly in South Brooklyn—that survive have largely been re-purposed as music venues, big-box retailers, churches, and is a popular conversion for these large spaces, as fitness centers and chain pharmacies. If you keep your eyes open, the architectural features of the old Brooklyn theatres occasionally pop out from the streetscapes, hiding behind Rite Aids and Walgreens.