北京天坛

Temple of Heaven

资料：

北京天坛1998年11月被列入《世界遗产名录》。

天坛位于北京城南端，是明清两代皇帝祭祀天地之神和祈祷五谷丰收的地方。它的严谨的建筑布局，奇特的建筑结构，瑰丽的建筑装饰，被认为是我国现存的一组最精致，最美丽的古建筑群，天坛不仅是中国古建筑中的明珠，也是世界建筑史上的瑰宝。

天坛东西长1700米，南北宽1600米，总面积为273万平方米。天坛包括圜丘和祈谷二坛，围墙分内外两层，呈回字形。北围墙为弧圆形，南围墙与东西墙成直角相交，为方形。这种南方北圆，通称“天地墙”，象徵古代“天圆地方”之说。外坛墙东、南、北三面均没有门，只有西边修两座大门－－圜丘坛门和祈谷坛门（也称天坛门）。而内坛墙四周则有东、南、西、北四座天门。内坛建有祭坛和斋宫，并有一道东西横墙，南为圜丘坛，北为祈谷坛。

除祈谷坛和圜丘坛之外，天坛还有两组与众不同的建筑群，即斋宫和神乐署。 斋宫实际是座小皇宫，是专供皇帝举行祭祀礼前斋戒时居住的宫殿，也有城河围护。 神乐署则是隶属于礼部太常寺之下，专门负责祭祀时进行礼乐演奏的官署。它是一个常设机构，拥有数百人的乐队和舞队，平时进行排练，祭祀时负责礼乐。署衙的位置在外坛西部，与斋宫隔墙相邻，是一组标准的衙署建筑。

天坛面积辽阔，相当于紫禁城的四倍。在极小占地的建筑周围种植着苍松翠柏，深绿颜色在古代表示崇敬、追念和祈求之意。这也是在坛、庙、陵寝种植松柏的原因。

进入天坛，树木葱郁，尤其在南北轴线和建筑群附近，更是古柏参天，树冠相接，把祭坛烘托得十分肃穆。据统计，天坛仅古柏就有4000株。

祈谷坛上为祈年殿。殿高33米，直径24.2米，宏伟壮观，气度非凡，是昔日北京的最高建筑之一。祈年殿建于明永乐十八年（1420年）取名大祀殿，为宽12间，纵深36间的黄瓦玉陛重檐垂脊的方形大殿。大祀殿与其说是祭坛，不如说是一座宫殿，后来嘉靖皇帝旨意拆除，并于1545年在大祀殿原址上建成大享殿，清王朝建立后，用它来举行祈谷礼。1751年，正式将大享殿更名为祈年殿。清干隆十六年（1751年）重修祈年殿，更换蓝瓦金顶。光绪十五年（1889年）八月二十四日，雷雨交加，祈年殿不幸被雷电击中，焚烧。因楹柱为檀香木，香飘数里。

据传，北京古建筑材料中有着名的四宝，即祈年殿沉香木楹柱，太庙前殿正中三间沉香木梁柱，颐和园佛香阁内铁梨木通天柱，谐趣园中涵远堂内沉香木装修格扇。现在所看到的祈年殿，是雷击后重修的，其形状和结构都与原来的一样。

祈年殿是一座宏伟而又极具民族风格的独特建筑，鎏金宝顶三层出檐的圆形攒尖式屋顶，覆盖着象徵“天”的蓝色琉璃瓦，层层向上收缩，檐下的木结构用和玺彩绘，坐落在汉白玉石基座上，远远望去，色彩对比强烈而和谐，上下形状统一而富于变化。它的构造比皇穹宇复杂，外部是三层高阁，内部则是层层相叠而环接的穹顶式，仿佛像砖砌的券殿，但又没有一砖一石，全部采用木结构，28根大柱支撑着整个殿顶的重量。内外楹柱各12根，中间四根楹柱叫通天柱或龙井柱，高18.5米，大头直径1.2米，古镜式的柱础，海水宝相花的柱身，沥粉堆金，支撑着殿顶中央的“九龙藻井”。

三音石：皇穹宇殿门外是一条由大长方石铺成的甬路，站在甬道第三块石板上，敝开殿门，并将全殿窗户紧闭，使殿门到殿内正中神龛之间没有任何障碍物，然后面对殿门说话，就可以听到非常洪亮的三声回声，而且站在殿外任何地方都可以听到。由于这声音是在供奉“皇天上帝”的建筑里发出来的，而且回声很大，因而就有“人间偶语，天闻若雷”之说。于是又称这些石板为“天闻若雷石”。还称这些石板为“三才石”，即取天、地、人三才之意。人们必须是站在人石上说话，为让“皇天上帝”听到，还必须打开殿门，而说话的回声便是“皇天上帝”的回答。

其实，这种奇妙的现象，正是因为皇穹宇的殿门高，而石阶下面的第三块石板和殿门以及殿内神龛上面的殿顶形成一条直角三角形的斜边。站在第三块石板上说话，声波可以沿着斜线直接传入殿内，碰到圆形殿壁、殿顶后再返回殿外。又因第三块石板位于垣墙的中心，所以站在这里击掌，都能听到它的回声，只是由于声波传播的距离不同，所以才会听到次数不同的回声。由于其他石板与殿门和殿内的壁三点之间难以形成直角三角形的斜线，所以即使站在那里的其它石板上击掌或说话，就不可能听到回声。

回音壁就是皇穹宇的围墙。墙高3.72米，厚0.9米，直径61.5米，周长193.2米。墙壁是用磨砖对缝砌成的，墙头覆着蓝色琉璃瓦。围墙的弧度十分规则，墙面极其光滑整齐，对声波的折射是十分规则的。只要两个人分别站在东、西配殿后，贴墙而立，一个人靠墙向北说话，声波就会沿着墙壁连续折射前进，传到一、二百米的另一端，无论说话声音多小，也可以使对方听得清清楚楚，而且声音悠长，堪称奇趣，给人造成一种“天人感应”的神秘气氛。所以称之为“回音壁”。

圜丘坛在天坛南半部，始建于嘉靖九年（1530年），坐北朝南，四周绕以红色宫墙，上饰绿色琉璃瓦，俗称“子墙”。子墙四周各有一大门。北门叫成贞门，也称北天门；东门叫泰元门，也称东天门；西门叫广利门，也称西天门。南面正门叫昭亭门，也称南天门。每座门上题有满汉合璧门额。将各门名称的第二个字顺序排列为元、享、利、贞。这种排列据是据《周易》的“干卦四德”而定。“元”，代表始生万物，天地生物无偏私；“享”为万物生长繁茂享通；“利”，为天地阴阳相合，从而使万物生长各得其宜；“贞”，为天地阴阳保持相合而不偏，以使万物能够正固而持久。

皇帝每年祭天时，都从西边牌楼下轿，然后步入昭亭门，进昭亭门到圜丘坛。四周绕有两层名叫 墙的蓝色琉璃瓦矮墙。第一层墙为方形叫外；第二层墙为圆形叫内 ，象徵“天圆地方”。 内中央处，就是祭天台(也叫拜天台)，即圜丘台。

台面墁嵌九重石板，是象徵九重天的意思。所谓九重天，即：第一重日天；第二重月天；第三重金星天；第四重木星天；第五重水星天；第六重火星天；第七重土星天；第八重二十八宿天；第九重为宗动天，即上帝的起居室。每当祭天时，在坛台中央的太极石上供奉着皇天上帝牌，外面支搭蓝色缎幄帐，象徵皇天上帝居住在九天之上。古代中国认为天属阳，地属阴，引申开来，奇数属阳，偶数属阴。圜丘之所以都用奇数去构筑，就是因为它们都是阳数。而在10以下，最大的阳数是9，引申下去，9就是最大、无限、至极的意思。中国过去皇帝称为“九五之尊”，中国古诗词中也有“九霄”、“九天”、“九重天”……其中的“九”都是这个意思。圜丘在建筑设计中使用奇数，而且反复使用其中“九”的倍数，正是中国古代匠师对这种概念的运用和发挥，使“天”的观念能在祭祀建筑中更好地体现。

圜丘台中心是一块呈圆形的大理石板，称作天心石，也叫太极石。从中心向外围以扇形石。上坛共有九环，每环扇形石的数目都是“九”的倍数。一环的扇面石是9块、二环18块、三环27块，……九环81块取名九九。中层坛从第十环开始，即90块扇面石，直至十八环，为126块九组成，下层坛从十九环开始，至第二十七环，扇面石243块。三层坛共有378个“九”，合计用扇面石3402块。

站在圜丘台中间的圆心石上轻轻唤一声，就立即从四面八方传来回声，好似众人齐鸣，一呼百应。封建帝王附会说这是皇天上帝在向凡人发出“圣谕”。其实，这种现象是声波被阻的回音。从圆心石发出的声波传到四周的石栏以后，就同时从四周迅速反射回来，声波振动较大；又由于圜丘坛的半径较短，所以回声很快。据测试，从发音到声波返回到圆心的时间，总共只有0.07秒，所以站在圆心石上的人听起来，声音格外响亮。因此，圜丘坛上的圆心石又称为“亿兆景从石”。

The Temple of Heaven is a worthwhile visiting place in Beijing. It is much bigger than the Forbidden City and smaller than the Summer Palace with an area of about 2,700,000 square meters. The Temple was built in 1420 A.D. during the Ming Dynasty to offer sacrifice to Heaven. As Chinese emperors called themselves "The Son of Heaven" ,they dared not to build their own dwelling,"Forbidden City" bigger than a dwelling for Heaven.

The Temple of Heaven is enclosed with a long wall. The northern part within the wall is semicircular symbolizing the heavens and the southern part is square symbolizing the earth. The northern part is higher than the southern part. This design shows that the heaven is high and the earth is low and the design reflected an ancient Chinese thought of "The heaven is round and the earth is square".

The Temple is divided by two enclosed walls into inner part and outer part. The main buildings of the Temple lie at the south and north ends of the middle axis line of the inner part. The most magnificent buildings are The Circular Mound Altar (Yuanqiutan), Imperial Vault of Heaven (Huangqiongyu) and Hall of Prayer for Good Harvest (Qiniandian) from south to north. Also, there are some additional buildings like Three Echo Stones and Echo Wall.Almost all of the buildings are connected by a wide bridge called Vermilion Steps Bridge (Danbiqiao) or called Sacred Way.

The Circular Altar has three layered terraces with white marble. During the Ming and Qing Dynasties (1368 A.D. - 1911 A.D.), the emperors would offer sacrifice to Heaven on the day of the Winter Solstice every year. This ceremony was to thank Heaven and hope everything would be good in the future. The Hall of Prayer for Good Harvest is a big palace with round roof and three layers of eaves. Inside the Hall are 28 huge posts. The four posts along the inner circle represent four seasons-spring, summer, autumn and winter; the 12 posts along the middle circle represent the 12 months; and 12 posts along the outer circle represent 12 Shichen (Shichen is a means of counting time in ancient China. One Shichen in the past equaled two hours and a whole day was divided into 12 Shichens). The roof is covered with black, yellow and green colored glaze representing the heavens, the earth and everything on earth. The Hall has a base named Altar for Grain Prayers which is made of three layers of white marble and has a height of six meters. Another important building in Temple of Heaven is Imperial Vault of Heaven. If you look at it from far away, you will find that the Vault is like a blue umbrella with gold head. The structure of it is like that of Hall of Prayer for Good Harvest, but smaller in size. The structure was made of bricks and timber. The Vault was used to place memorial tablets of Gods. White marble railings surround the vault.

The Vermilion Steps Bridge connects the Hall of Prayer for Good Harvest and the Imperial Vault of Heaven. The south end of the Bridge is lower than its north end. The emperors in the past believed that they could go to heaven through this Bridge, which is why this bridge is also called Sacred Way. A Yu Route and a Wang Route are on two sides of the Sacred Way. The former one is only for the emperors to walk on and the later one is for the princes and the high officials to pass.

Three Echo Stones is outside of the gate of the Imperial Vault of Heaven. If you speak facing the Vault while standing on the first stone, you will hear one echo; standing on the second and then the third stone, you will hear two and three echoes respectively.

Another interesting and famous place for you to visit is called Echo Wall owning special feature. The wall encloses the Imperial Vault of Heaven. Its perimeter is 193 meters.

If you and your friend stand at the east and the west roots of the wall respectively and you whisper a word, then your friend will hear clearly what you say. Isn't it interesting? The phenomenon utilizes the theory of sound wave.

Besides carefully designed buildings, there are also some other scenes that you can enjoy like Nine-Dragon Cypress. It got its name from branches which look like nine dragons wind with each other. It was said that the cypress was planted more than 500 years ago. Really, a grandfather tree!