The Dalai Lama took part in a symbolic walk across the Peace Bridge in Derry with leaders of local churches and with his friend Richard Moore of the charity, Children in Crossfire.
Up to 300 local children formed a guard of honour as they walked across the bridge from cityside to waterside.
Mr Moore invited the Dalai Lama to Derry.
He said that he hoped that his presence in the city would send out a message about how far Derry had come but that we could not take peace for granted.
The Dalai Lama, who is a patron of Mr Moore's charity, spoke about the importance and the possibility of peace which he said we must create.
He has said there is no alternative to the peace process during a visit to Northern Ireland.
People have to work and live together and refrain from acting like animals, he said.
The Dalai Lama said: "There is no other alternative to the peace process, there is no other choice - you have to work and live together so we should not act like animals," he said.
The Serpentine Pedestrian peace bridge was opened in 2011.
It cost £14 million (€16.3m) to build and is the length of two-and-a-half football pitches.
Before crossing the bridge, the Dalai Lama met Catholic and Protestant church leaders, including Monsignor Eamon Martin.
At the other end he was presented with a gift by two children.
He attended an event called Culture Of Compassion at a former army barracks turned civic space in the city and give a public address.
The Dalai Lama last visited the city in 2007 when he attended anniversary celebrations for the charity Children In Crossfire, which is organising today's event.
The charity promotes early childhood care and development in some of the poorest countries in the world and its patron is Tibet's spiritual leader.
Richard Moore, the organisation's director, met the Dalai Lama in India, where he is in exile from Chinese-ruled Tibet.
Mr Moore was shot and blinded by a British soldier 40 years ago.
He travelled to meet the Dalai Lama with the man who shot him after they befriended each other.