one-mile walk哪里错了

前面要加冠词a a one-mile walk
After a 10-mile walk into the hills one finally reaches a piece of land and two small houses so hidden in the thick over-grown forest that only a handful of people know Dorothea is there.
向山里走大约10英里,终于看到了一小块土地,两间小房子.山里林深叶茂,多罗西亚的小房子几乎完全被遮住了,只有很少几个人知道她住在那里.
after a 10-mile walk into the hills one finally reaches a piece of land and two small houses so hidden in the thick over-grown forest that only a handful of people know Dorothea is there.
经过10英里的步行到山上一终于到达一块地和两个小房子,让隐藏在厚厚的过度增长,多萝西娅在那里.