Here there was but room enough for the road and the stream, whose bed was several feet below the causeway.

A few hundred yards farther, the gorge widened out a bit, and in the moonlight they could see the wall of the fort stretching before them, and a square building standing close to it.
"That is the guard house, no doubt," Dick said, in low tones.

"It is too close to be pleasant, if we have to attack the sentry." Very carefully, they picked their way among the rocks, until close to the wall; then Dick gave a low exclamation of disappointment.

The stream ran through a culvert, some twelve feet wide and ten feet high, but this was closed by iron bars, crossing each other at intervals of only five or six inches, the lower ends of the perpendicular bars being fixed in a stone dam, extending across the bed of the stream.
Dick waded across the pool formed by the dam, and felt the bars, but found them perfectly solid and strong.
"It is no good, Surajah," he said, when he returned.

"There is no getting through there.