When was Zhou Ding's grave excavated?

Discovered in the 1970s. Zhoudingling Tourist Area consists of Zhou Ding Mausoleum, Princess Mausoleum and surrounding natural landscape in Ming Dynasty. Its west is the mountain of Wanshan, that is, the head of the east of Ci Mountain, also known as the famous mountain, and its east is the vast Huanghuai Plain. It has beautiful scenery, many scenic spots and rich cultural connotations. Among them, the tomb of the king and the tomb of the princess of the king are the main scenic spots of key cultural relics protection units and tourist areas in Henan Province. Zhou Dingling, commonly known as "Zhu Wangfen", is located at the east foot of Laoshan Ping in Wuliang Town. Zhou Dingling is the tomb of Zhu Ellipse, the fifth son of Zhu Yuanzhang and the younger brother of Judy in Ming Taizu. Zhu Ellipse Hongwu lived in Kaifeng for fourteen years, and his palace was located in the Forbidden City in the Northern Song Dynasty. Because his country was named Zhou and posthumous title was fixed, he was called the fixed king. When he was alive, Henan suffered from famine for years. He selected the leaves, stems and roots of edible weeds in Henan and made a book with pictures and texts. The spread of Herbicide is a contribution to ancient science.