Answer:
Fourth Dynasty
Step-by-step explanation:
Although the kings of III dynasty of old kingdom started building pyramid like structures but it were the Pharaohs of IV dynasty who build the largest and beautiful and true pyramids. Their period is being called the golden age or "the age of pyramid". It was during the IV dynasty the Pharaoh Khufu built the Great Pyramid of Giza which is one of the seven wonders of the World.