在黑龙江省东宁县有一个军事要塞,是当年日本关东军在我国东北修建的最大要塞。自1938年日军动用了大批人力、物力和财力,沿中国边境线修筑地下工事。直到1945年这一庞大工程还未彻底竣工,日本就投降了。由于种种原因,要塞的建筑规模、内部设施,成了历史之谜。 There was a military fort in Dongning County, Heilongjiang Province, the largest fortress Japan’s Kwantung Army built in northeast China. Since 1938, the Japanese army mobilized a large amount of manpower, material and financial resources to build underground fortifications along the Chinese border. Japan did not surrender until the huge project was completed in 1945. Due to various reasons, the fortress’s building scale and internal facilities have become a mystery of history.