The Egyptian pyramids are ancient structures located in Egypt. Approximately 80 pyramids were built within the Kingdom of Kush, now located in the modern country of Sudan. Of those located in modern Egypt, most were built as tombs for the country's pharaohs and their consorts during the Old and Middle Kingdom periods. The most famous Egyptian pyramids are those found at Giza, on the outskirts of Cairo. Several of the Giza pyramids are counted among the largest structures ever built.[9] The Pyramid of Khufu is the largest Egyptian pyramid. It is the only one of the Seven Wonders of the Ancient World still in existence, despite its being the oldest wonder of the list. The design of the earliest Egyptian pyramids around 3500 BC is very different missing the sharp edge on the top. The pyramids gradually evolve from stepped designs to a perfect pyramid in the later ages of the Egyptian kingdom. The earliest pyramids resemble the design of the pyramidal tombs with cut top of the Thracians in Eastern Europe. The proportions in the measures of the pyramids in Egypt also follows the earlier built pyramidal tombs of the people of Thrace in their period 6000 - 4000 BC and later. When these magnificent structures reached Egypt they reached their culmination, thanks to the abundant presence of materials which allow making of huge massive blocks.