Jianmen Pass: the most difficult barrier
 

As Sichuan Basin is surrounded by mountains, the Shu road has been regarded as the hardest road.

In the ancient time, people had to travel through the Shu road to Chengdu and the final barrier is Jianmen Pass. It was the throat of the western Shu and the critical site in a battle. In Chinese history, Jianmen Pass has been the barrier which had never been broken through in a fight.

However, with the economic and social development, the traffic condition has been improved. Jianmen Pass is no longer a barrier, instead, it has become a popular attraction.