Final answer:
A gopuram is a monumental, ornate gateway tower to a Hindu temple enclosure. It serves as the entrance to the temple complex and is usually elaborately decorated.
Step-by-step explanation:
A monumental, ornate gateway tower to a Hindu temple enclosure is called a Gopuram. Gopurams are a prominent feature of South Indian temple architecture and serve as the entrance to the temple complex. They are often elaborately decorated with intricate carvings and sculptures.