평택시 청북면 옥길리의 해발 104.7m인 무성산에 있다. 북쪽에는 발안천이 흐르고, 남으로는 자미산과 비파산으로 이어지는 능선이 아산만 방향으로 뻗어있어 동서 교통로를 차단하는 요충지에 해당한다.

무성산성은 무성산의 9부능선을 따라 쌓았다. 평면 형태는 장타원형에 일부가 돌출된 다각형이다. 성벽은 흙으로 쌓은 토성이며 전체 둘레는 547m다. 성벽은 기초를 편평하게 정리하고 그 위에 점토를 다져 수평을 맞춘 후 점토와 모래를 교대로 쌓아 올렸다. 북치성 주변에서는 기초부에서 와적층(瓦積層)이 확인되었다.

모든 성곽은 축성 당시의 토목기술로 쌓았다. 따라서 축성주체와 시기에 따라 공통적인 특성이 확인된다. 성벽 하단에서 확인되는 기와는 무성산성이 고려초에 축성되었음을 말해준다. 이 시기의 토성들은 기단석열을 조성하고 판축공법으로 중심토루를 조성하고 와적층을 깔고 내외피토루를 덧붙여 쌓는 공통적인 공법이 적용되었다. 성벽에서는 문지와 치성, 장대지, 수구지, 건물지 등이 확인되고 있다. 무성산성은 통일신라 말에서 고려초 평택지역의 치소의 변천과정과 관련이 있는 것으로 보인다. 규모는 현의 치소성급에 해당한다. 무성산성은 석성에서 토성으로, 산성에서 평산성으로 변화되는 치소성의 역사적인 변천과정을 보여주는 중요한 유적이다.

The fortress site is located on Museongsan Mountain (alt. 104.7 m) in Okgil-ri, Cheongbuk-myeon, Pyeongtaek-si. Balancheon Stream flows to the north, and to the south is a ridge that connects Jamisan Mountain and Bipasan Mountain and stretches out toward Asanman Bay. The fortress and neighboring region served to block transportation from the east and west. Museongsanseong Fortress was built along the upper ridges of Museongsan Mountain. It is formed in a relatively flat, long, oval shape with some parts protruding outward. The wall, piled up with soil, has an overall circumference of 547 m. In order to create the fortress’s foundation, the land was leveled and packed with clay, with alternate piles of clay and sand. Roof tiles were found in the area near Bukchiseong Castle, confirming the construction of the basic layer. Fortresses typically reflect the civil engineering technologies that were available at the time in which they were built. Therefore, fortresses and auxiliary structures typically have common characteristics on based on who built them and the period in which they were built. The roof tiles found on site were used to confirm that the lower wall of the Museongsanseong Fortress was built in the Early Goryeo Period. Earthen fortresses from this period were built using the common techniques of: creating rows of stylobate stones; forming the central earthen structure using the panchukgongbeop technique (technique of strengthening structures by piling and packing soil); placing roof tiles in layers; and adding inner and outer protrusions. Gate sites, chiseong (structures protruding out from the castle wall), jangdaeji (pole sites), suguji (water draining facilities) and other building sites were also found along the castle wall. It appears that Museongsanseong Fortress may have been built during a time when the defense strategies used in the Pyeongtaek region were changing from the Late Unified Silla Period up to the Early Goryeo Period. The size of the defense fortress is equivalent to that of a hyeon (administrative subdivision). Museongsanseong Fortress is an important historic site that shows the historic transition of defense fortresses from stone fortresses to earthen fortresses and from peaked fortresses to flat fortresses.

位于平泽市青北面玉吉里海拔104.7米的武城山上， 北侧有发安川流淌，南侧由兹美山和琵琶山相连的山脊绵延至牙山湾方向，是切断东西交通的要地。 武城山城沿着武城山山脊的十分之九处建造而成，平面形态为长椭圆形中部分突出的多边形，城墙是用泥土堆砌的土城，全部周长为547米。城墙地基整理得较为平坦，在其上夯实黏土并整理平整后，交替堆砌黏土和沙子。在北雉城周围，于地基部发现了瓦积层。 所有城郭均使用筑城当时的土木技术建造而成，因此，根据筑城主体和时期，可以确认其共同特性。在城墙下端发现的屋瓦表明武城山城建于高丽初期。这一时期的土城均使用了相同工法，即建造基坛石列，然后用版筑工法建造中心土垒，并铺设瓦积层，最后叠加内外层土垒。城墙内发现了门址和雉城、将台址、水口址、建筑址等。据推测，武城山城可能与统一新罗末期到高丽初期平泽地区治所的变迁过程有关，其规模相当于县的治所城级别。武城山城是展现治所城从石城变为土城、从山城变为平山城的历史变迁过程的重要遗迹。

ピョンテク(平沢)市チョンブク(青北)面オクキル(玉吉)里の海抜104.7mに位置するムソン(武城)山にある。北にはパルアン（発安）川が流れ、南にはチャミ（玆美）山やピパ（琵琶）山へと続く稜線がアサン(牙山)湾方向に伸びており、東西の交通路も位置する要衝地である。 ムソン(武城)山城はムソン(武城)山9合目に築かれた。平面形態は長楕円形の一部が突出した多角形である。土で積み上げて築かれた土城であり、全体の長さは547m。城壁は土地を平らにして基礎を作り、その上に粘土を固めて水平を合わせた後、粘土と砂を交互に積み上げて作られた。プクチ（北雉）城の周りの基礎部では瓦積層が確認された。 城郭はすべて築城当時の土木技術で築かれたものである。したがって、築城主体と時期ごとの共通の特性が確認される。城壁の下段にある瓦は、ムソン(武城)山城が高麗初期に築城されたことを示している。この時期の土城は基壇石列を作り、版築工法で中心の土塁を造成し、瓦積層を敷いて内外に土塁を積み上げるという共通した工法が採用された。城壁からは門跡と雉城（城壁に付属した小さな垣根）・将台跡・水口跡・建物跡などが確認されている。ムソン(武城)山城は、統一新羅末期から高麗初期のピョンテク(平沢)地域に位置した治所（官庁）の変遷過程に関係すると考えられる。大きさは県の治所城級に相当する。ムソン(武城)山城は石城から土城に、山城から平山城に変化する治所城の歴史的変遷過程を示す重要な遺跡だ。