The road --- that foot of the mountain 为什么要填leads to,

lead to 在这里是通向的意思
All roads lead to Rome.
条条大道通罗马.
lead表示通向的时候后面要跟个介词 to或者into
That door leads into the garden.
那扇门通向花园.
that foot应该是特指吧 这里that是那个,可以把他理解成the foot of the mountain
我是这么想哦~