Iglesia ni Cristo church buildings primarily serve as places of worship and are used for other religious functions. These are described by "Culture and Customs of the Philippines", a book published by Greenwood Publishing Group, as structures "which employ exterior neo-Gothic vertical support columns with tall narrow windows between, interlocking trapezoids, and rosette motifs, as well as tower and spires." There are multiple entrances leading to the main sanctuary, where males and females sit on either side of the aisle facing a dais where sermons are made. The choir loft is located behind the dais, and in larger churches, a baptistry with pools for immersion baptism is located at the back of the church. Meanwhile, Fernando Nakpil-Zialcita, an anthropologist from Ateneo de Manila University, said that INC churches can be uniquely identified for "its exuberant use of fanciful forms and ornaments a brilliant white facade whose silhouette is a cusped Gothic arch or a flattened Saracenic arch." The distinctive spires represent "the reaching out of the faithful to God." Prominent architects, such as Juan Nakpil (a National Artist of the Philippines for architecture) and Carlos A. Santos-Viola, had been involved in designing INC churches while the Engineering and Construction Department of INC, established in 1971, oversees the uniformity in design of church buildings.