四神相応（しじんそうおう）は、中国・朝鮮・日本において、天の四方の方角を司る「四神」の存在に最もふさわしいと伝統的に信じられてきた地勢や地相のことをいう。四地相応ともいう。なお四神に中央に「黄龍」（おうりゅう）、あるいは麒麟を加えたものが「五神」（ごじん）と呼ばれている。ただし現代では、その四神と現実の地形との対応付けについて、中国や韓国・朝鮮と日本では大きく異なっている。中国・朝鮮中国や朝鮮での風水における四神相応は、背後に山、前方に海、湖沼、河川の水（すい）が配置されている背山臨水の地を、左右から砂（さ）と呼ばれる丘陵もしくは背後の山よりも低い山で囲むことで蔵風聚水（風を蓄え水を集める）の形態となっているものをいう。この場合の四神は、背後の山が玄武、前方の水が朱雀、玄武を背にして左側の砂が青龍、右側が白虎である。日本の京都においても、北の丹沢山地を玄武、東の左大文字山を青龍砂、西の嵐山を白虎砂、南にあった巨椋池を朱雀とする対応付けが可能で、標準的な風水の観点から正しく京都は四神相応の地であった。ただし巨椋池が完全に埋め立てられてしまったために、京都の四神相応は破壊されている。なおかって朱雀大路を見通すことのできた船岡山は、玄武とするには小規模である。標準的な風水の観点では、船岡山を玄武を伝ってやってくる山龍が目指す星峰と解釈している。日本現代の日本では次表のような、四神を「山川道澤」に対応させる解釈が一般に流布している。しかし、この対応付けは古来から定まっていたというわけではない。「四神＝山川道澤」説の典拠となっているのは、『作庭記』である。『作庭記』は寝殿造を念頭においた庭園の作り方を述べた書物であり、理想の庭園の姿として「四神＝山川道澤」説を記述する。そして四神としての山川道澤がない場合に、特定の種類の樹木を特定の本数植えることで「四神＝山川道澤」の代用となることを説いている。現在の日本で四神を「山川道澤」に対応させる解釈が一般的となったのは、平安京をモデルとして、青龍＝鴨川(淀川水系)、白虎＝山陰道、朱雀＝巨椋池(おぐらいけ)、玄武＝船岡山の対応付けが比較的うまく行ったと考えられるようになってからである。しかし『作庭記』自体には平安京についての言及はなく、ましてや山川道澤の具体的地名などはまったく記されていない。『作庭記』はその内容から平安時代末期の作とされており、「四神＝山川道澤」説は平安時代末期までしか遡り得ないのが現状である。そのため、同説が8世紀後葉に建設された平安京選地の思想的背景であるとの前提に立った主張については裏付けがないことに注意が必要である。さらに、平安京でうまく行ったとされる山川道澤との対応付けは、江戸時代以降に主張されるようになったものであり、それが一般的な解釈とされるようになったのはようやく明治時代になってからである。つまり、江戸時代以前の都市デザインが四神相応となるように設計されていても、その四神が山川道澤であるとは考えにくい。例えば平城京はその建都にあたっての詔勅に、「方今、平城之地、四禽叶図、三山作鎮、亀筮並従。（方に今、平城の地、四禽図に叶ひ、三山鎮を作し、亀筮並に従ふ。）」とある。この「四禽図に叶ひ」とは四神相応のことであり、奈良時代には平城京が四神相応の地であると考えられていたことを確認できる。平城京の立地は、平安京で説かれるような山川道澤にはあてはまらない。しかしそれを四神相応とする以上、奈良時代には別の解釈がとられていたことになる。また、鎌倉時代後期の詞林采葉抄では「その中山を玄武に当て、貴人金爐を朱雀に当て、・・・」とあり、朱雀に「貴人金爐」が対応付けられていることがわかる。さらに『柳営秘鑑』によれば、「風此江戸城、天下の城の格に叶ひ、其土地は四神相応に相叶ゑり」と記されている。『柳営秘鑑』の著者である菊池弥門にとって、江戸城は四神相応の地に建設された城郭である。しかし、「四神＝山川道澤」説を採用するとすれば、どう贔屓目にみても朱雀となりそうな東京湾は東から南東を経て南への広りがあるわけだし、白虎となりそうな甲州街道も単に西に延びているだけである。このような地形をもって、「四神＝山川道澤」説に合致しているとするのは、牽強付会というべきだろう。さらに言えば、姫路城や福山城(備後国)、熊本城などを「山川道澤」の四神相応とするもの同様に後世に創られた解釈である。名古屋城についても『金城温古録』では、「名府御城の如きは、道を四道に開かれて、四方より人民輻湊する事、恰も天下の城の如く十里に嶮地を置き、東は山、南は海、西北は木曾川あり、その中間、三五里を隔て要害設し給ふ（中略）、先は東は八事山の砦柵、西は佐屋、清州の陣屋（中略）、城、場、郭の三を備へ、四神相応の要地の城とは、これを申奉るなるべし」と記述されている。『金城温古録』で語られている四神相応もまた「山川道澤」ではない。また古代中国の風水では特定の方位について固定した吉凶をとる考えはなく、鬼門・裏鬼門を忌むのは日本独自の考え方である。そういう点で『竈門山旧記』を根拠として、竈門神社が大宰府の鬼門を護るために大宰府建設時に創建されたという記述から、大宰府が風水に則って作られたとする説は問題が多い。このように四神相応の解釈は古代から近世にかけて変化していき、古代中国の風水とは異なる独自のものであったと考えられる。大相撲-土俵上にある4つの色分けされた房は元来方屋の屋根を支えた4柱の名残であり四神を表している。

the term " shijin-so-o " refers to the topography and land physiognomy that are traditionally believed to be the best suited for the ' four gods ' that govern the four directions of the heavens in china , korea and japan .it is also called shichi-so-o topography .the four gods with an ' oryu ' ( yellow dragon ) or kirin at their center are called the ' go-jin ' ( five gods ) .however , the correspondence between the four gods and actual geography in japan differs greatly from that in china , south korea , and north korea .china and koreashijin-so-o topography in the feng shui of china and korea indicates the form of zofujusui ( storing wind and collecting water ) in which the terrain is enclosed by having tall mountains at the back ( haizan-rinsui ) , a lake , river , or sea in the front ( sui ) , and smaller hills or mountains ( sa ) on both sides .the four gods in this case are as follows : the mountains in the back are genbu ( black warrior ) ; sui in front is suzaku ( a red phoenix ) ; the left sa with genbu in the background is seiryu ( a blue dragon ) and the right sa is byakko ( a white tiger ) .in kyoto , japan it was possible to have the following association : the tanzawa mountains in the north as genbu , mt . hidari-daimonji as seiryusa , arashiyama in the west as byakkosa and ogura-ike pond in the south as suzaku ; therefore , kyoto was a land of shijin-so-o topography exactly from the perspective of the feng shui standard .however , ogura-ike pond was completely consumed by landfills , which broke the shijin-so-o topography of kyoto .mt . funaoka , which once overlooked suzaku-oji avenue , is a little too small for genbu .in the standard viewpoint of feng shui , mt . funaoka is interpreted as seiho , to which sanryu , a dragon of mountains , is headed via genbu .japanin modern japan , the interpretation that the four gods are related to ' mountain , river , road and lake , ' as shown in the following table , is generally accepted .however , this association has not necessarily been settled since ancient times .the " sakuteiki gardening book " is source of the theory that equates the four gods to ' mountain , river , road and lake . '" sakuteiki gardening book " explains how to create a garden , taking shinden-zukuri ( a style of architecture for the residence of court nobles ) into consideration , in which the theory of ' four gods = mountain , river , road and lake ' is described as the ideal basis for such a garden .it also explains that planting certain kinds of trees can substitute ' the four gods = mountain , river , road and lake ' in the event there is no mountain , river , road and lake to represent the four gods .the interpretation that the four gods are related to ' mountain , river , road and lake ' has been generally accepted in modern japan , since the association of seiryu = kamo-gawa river ( the yodo-gawa river system ) , byakko = sanin-do road , suzaku = ogura-ike pond and genbu = mt . funaoka was relatively successful with heian-kyo as a model .in fact , " sakuteiki gardening book " mentions nothing about heian-kyo , much less the specific places of the mountain , river , road and lake .it is said that " sakuteiki gardening book " was created at the end of the heian period , judging by its content , which is why the theory of ' four gods = mountain , river , road and lake ' can only date back to the end of the heian period .therefore , we need to pay attention to the fact that there is no proof of the argument based on the assumption that this theory is the ideological background for choosing the land for heian-kyo , which was built in the late eighth century .moreover , the association of mountain , river , road and lake , as allegedly done well into the heian-kyo , has been claimed since the edo period , which became the general interpretation later in the meiji period .in fact , even though a city prior to the edo period would have been designed to match the shijin-so-o topography , it is very unlikely that the four gods were mountain , river , road and lake .for example , in the imperial rescript , when building the capital , heijo-kyo is described as follows :right now , the place of heijo is in accordance with the painting of four beasts ; three mountains assuage things , and turtle augury tells the same . 'the phrase ' accordance with the painting of four beasts ' here means shijin-so-o topography , which confirms that during the nara period heijo-kyo was considered to be the place having shijin-so-o topography .the location of heijo-kyo doesn 't apply to a mountain , river , road and lake as described for heian-kyo .however , as long as it is associated with shijin-so-o topography it is likely that another interpretation would have been accepted during the nara period .shirin saiyo-sho commentary in the late kamakura period mentions that ' the central mountains are related to genbu , and the people , panoply and oven are related to suzaku ... , ' which shows that suzaku was associated with ' people , panoply and oven . 'moreover , " ryueihikan " mentions that ' winds of the edo castle merit the position of the world 's castle , and its land coincides with shijin-so-o topography ' .the author of " ryueihikan " , yamon kikuchi , considered that edo castle was built on the land coinciding with shijin-so-o topography .but if applying the theory that ' four gods = mountain , river , road and lake ' , then tokyo bay , which is likely to be suzaku ( god said to rule over the southern heavens ) , spreads from east to south-by-southeast , and koshu-kaido road , which is likely to be byakko ( god said to rule over the western heavens ) , only stretches to the west no matter how you see them in their favor . "it is far-fetched to say that such geography matches the theory of ' four gods = mountain , river , road and lake . 'furthermore , the interpretation that himeji castle , fukuyama castle ( bingo-no-kuni ) or kumamoto castle matches the shijin-so-o topography of ' mountain , river , road and lake ' theory emerged later .as for nagoya castle , " kinjo-onko-roku records " mentions that ' your great castle has roads open to four directions , and people gather from all over the world ; like the world 's castle , it places chokepoints at about 40 kilometers ; it has mountains in the east , the sea in the south , kiso-gawa river in the northwest , and in between it installs strategic stops at a distance of about 140 kilometers ( omission ) ; lying ahead , a fort on mt . yagoto in the east , saya and the armed camp in kiyosu in the west ( omission ) ; with the castle , camps and walls , these indicate the key castle of shijin-so-o topography . 'the shijin-so-o topography described in " kinjo-onko-roku records " is not ' mountain , river , road and lake , ' either .there is no concept of certain fortune on a certain direction in the feng shui of ancient china , so it is an original japanese concept to abhor kimon ( the direction of northeast , called an ogre gate ) and urakimon ( the direction of southwest which is the opposite side of kimon ) .in this sense , one must doubt the theory expressed in " kamadoyama kyuki histroy book " that dazaifu tenmangu shrine was made based on feng shui according to the description that kamado-jinja shrine was made to protect kimon of dazaifu tenmangu shrine at the time of its construction .this is how the interpretation of shijin-so-o topography has changed from ancient times to the early modern times , and it is believed to be unique and different from the feng shui of ancient china .grand sumo - the four tassels with different colors above the sumo ring were relics of four pillars that originally held up the roof of kataya , indicating the four gods .