The most famous of Harlem's more than 400 houses of worship is this Baptist church, founded downtown in 1808 by African-American and Ethiopian merchants. It was moved uptown to Harlem back in the 1920s by Adam Clayton Powell Sr., who built it into the largest Protestant congregation -- white or black -- in America. His son, Adam Clayton Powell Jr. (for whom the adjoining boulevard was named), carried on his tradition, and also became the first-ever black U.S. congressman. Abyssinian is now the domain of the fiery, activist-minded Rev. Calvin O. Butts, whom the chamber of commerce has declared a "Living Treasure." The Sunday-morning services -- at 9 and 11am -- offer a wonderful opportunity to experience the Harlem gospel tradition.