본고는 하동 두우산에 소재하는 봉수에 대한 소개글이다. 하동군 금성면 두우산 정상부에서 확인된 봉수 3기는 남-북 능선을 따라 위치하며, 추정 건물지 1기도 함께 확인되었다. 특이한 것은 봉수의 구조ㆍ형태가 각각 다르다. 이들 중 연대(煙臺)형 봉수를 추정 계화산봉수(1호 봉수), 방호벽 내부가 빈 평면 원형의 봉수를 두우산봉수1(2호 봉수), 두우산봉수2(봉수 3호)라 명명하였다. 1호 봉수는 방호벽이 확인되지 않고 연대만 확인된다. 연대의 평면형태는 타원형이다. 1호 봉수 주변에서는 채석지와 음각으로 새겨진 劍모양이 확인된다. 이 검모양은 당시 봉수군이 휴대하고 다녔던 고리칼(還刀)를 표현한 것으로 보인다. 두우산 정상부 쪽에서 1호 봉수와 관련된 건물지가 확인되었다. 추정 건물지 담장석축 주변으로 우물로 추정되는 석축 2기와 말굽형 석축, 채전지로 추정되는 석축 3기가 확인된다. 2호 봉수의 평면형태는 중앙이 비어있는 도넛형태로 축조된 것이 특징적이다. 봉수대는 방호벽, 방호벽 내 배수시설로 추정되는 호와 출입시설, 석곽형태로 조성된 추정 창고시설 등이 확인된다. 봉수 3호는 1호 봉수와 2호에 비해 훼손이 심해 정확한 구조를 알 수 없지만, 연대의 북동쪽과 남서쪽에서 가공한 석재의 면을 맞추어 놓은 석렬이 확인되어 관련 시설로 추정된다. 본고에서는 그동안 봉수의 조사사례가 미흡했던 하동지역 봉수의 형태, 규모, 구조등을 파악하는데 치중하였다. 향후 대상 지역 봉수의 정밀한 조사와 기능적 접근을 통해 봉수의 통시적 연구가 필요할 것으로 사료된다.

With the accumulations of outcomes from archaeological excavations of mountain fortress of three kingdoms period, there have been studies about time-periodic territory range of mountain fortress, difference in the way(method) of construction, defence system and so on from various points of view. This is an empirical study on the construction method of the valley part of stone fortress. First of all, it is required to secure large quantity of fresh water for those who lived at mountain fortress. Especially when builders of fortress construct a fortification at the valley part of stone fortress, in advance they must sufficiently consider several options including the establishment of sustainable water resources. First, when it comes to build a fortification on a ridge[or a slope] of a mountain, you have only to consider a vertical stress. However, when it comes to build a fortification at the valley part of a mountain, You must have more sufficient preparations for the constructing process. Because there are not only a vertical stress but also a horizontal pressure simultaneously. Second, a fortification of mountain fortress built by using unit building stone is a structure of masonry construction like brick construction, and the valley part of it is where the construction of the fortification begins. Third, when it comes to build a fortification at the valley part of a mountain, it seems that they use a temporary method such as coffer dam in oder to prevent the collapse of the fortification due to heavy rain. Furthermore, in response to a horizontal pressure a fortification is built by the way of its plane make an arch, or by piling up the soil with the plate method(類似版築) and earthen wall harder method(敷葉) they increase cross-sectional area of the fortification and its cutoff capacity. In front direction they put the reservoir facility for the fear that the hydraulic pressure and earth pressure are directly transmitted to the fortification. The process of constructing the fortification at the valley part of a mountain is done in the same oder as follows; leveling of ground(整地) ⇨ construction of coffer dam ⇨ construction of the fortification between the both banks of the valley ⇨ construction of the fortification at bottom part of spill way(餘水路) between the both banks of the valley ⇨ construction of spill way(餘水路) & reservoir facility ⇨ construction of the fortification at upper part of spill way between the both banks of the valley. Coffer dam facility seems to be not only the protection device on occasion of flood but also an important criterion to measure the proper height of spill way or tailrace(放水路). This study has a meaningful significance in that it empirically examines the method of reduction of the horizontal pressure which the fortification at the valley part of a mountain takes, the date the construction was done, and wether the changes in climate such as heavy rainfall influence the process of construction.