Dengfeng Astro Observatory
Dengfeng Astro Observatory is located at Gaocheng Town，15 kilometers southeast of Denpfenq City，Henan is the most ancient as-tronomical observatory extant in China.
登封观星台位于河南省登封市城东南巧千米的告城镇，是中国现存最古老的天文台。Performing the functions of measuring the shadow cast by the sun，observing celestial bodies，and telling time，the Astro Ob-servatory is an ancient scientific heritage with significant research value.
该观星台具有测影、观星和记时等功能，是具有重要研究价值的古代科学遗产。
It was built in the 13th year of the Emperor Zhiyuan(AD 1276)，(in the Yuan)by Guo Shou-jing and Wang Xun as directed by the emperor, and was among the 27 astronomi-cal observatories in the country at that time.
该台为至元十三年(1276年)郭守敬、王询等人奉救所建，是当时全国修建的27个天文观测站之一。The observatory, of masonry con-strudion，consists of the platform body and the stone gnomon(commonly named as heaven measuring ruler) a square plane，the observatory is narrow in the top and large at the bottom. It is 12. 62m in overall the north of the observatory are two symmetrical step entrances for obser-vation.
台为砖石混合结构，由台身和石圭(俗称量天尺)两部分组成。台的平面呈方形，台体上小下大，通高12. 62米。台北设有两个对称的踏道口可以登台眺望。The center of the northern wall is built into a hollow groove that is perforated through from top to bot-tom,so the higher gnomon at the groove’s straight wall and the stone gnomon at the bottom constitute a se-ries of gnomon apparatus for measur-ing the length of the shadow cast by the sun.
北壁中间砌成一个上下直通的凹形直槽，凹槽直壁与横梁组成的高表与台下石圭形成一组测量日影长度的圭表装置。The stone gnomon at the bottom of the groove is connected with 36 blocks of blue stone from south to north，and is 31 .2m in length and 0. 58m in width. The gnomon is canned with two parallel two-way watercourses. To the south of the watercourses is a suction sump，and to the north a discharge sump. Each sump has scales for measuring the levelness.
槽底石圭自南向北由36方青石连接而成，长31.2米，宽0. 58米，上刻两条平行双股水道。水道南端有注水池，北端有泄水池，池中有刻度，用以测量水准。