It comes after the government signed a peace deal with the FARC rebel group, a deal four years in the making.
There was a mass to usher in a new era in Colombia.
After an estimated quarter-of-a-million people were killed in the longest armed conflict in South America, foreign dignitaries were on hand to witness the historic occasion.
Led by United Nations secretary-general Ban Ki-moon, they watched the government and the Revolutionary Armed Forces of Colombia, or FARC, sign a peace deal agreed to in June.
The agreement was reached after almost four years of talks in Cuba.
President Juan Manuel Santos and rebel leader Rodrigo Londono, known as Timochenko, signed the deal in the Caribbean town of Cartagena.
Both dressed in symbolic white, it was the first time they had shaken hands on Colombian soil.
They then used a pen made from a bullet to sign the agreement, which President Santos hailed.
"This is the last armed conflict in the whole of the Western Hemisphere, the oldest, the cruelest. The Cold War is really ending when the agreement is signed."
Rodrigo Londono, the FARC leader, says he hopes the agreement brings an end to armed conflict in Colombia.
"A population that has lived with this suffering among so many wars, during so many decades, could really dream of peace and social justice without losing the hope of seeing different paths, without armed conflict, through forgiveness and reconciliation."
Former presidential candidate Ingrid Betancourt had been kidnapped by FARC and held captive for six years.
But she says she supports the end to the fighting.
"People like me, victims of the war, we know that, in individual terms, there's no justice, true justice, for us. But I think that, when you put in balance the possibility that, in Colombia, the future generations won't be subject to violence as we were subject, I think that the gain is so enormous that it's easy to think that is the right thing to do."
The agreement allows amnesty for some rebel fighters and reduced sentences in exchange for cooperation with de-mining efforts, for example.
Five seats in the lower house of congress and five in the senate will also be awarded to the political party to transition out of FARC as an incentive for disarmament.
But President Santos says not everyone will be pleased.
"We negotiated the best deal possible, the best deal possible which will allow us to have peace. There are many people who are not happy, and this is something normal."
One of those is former president Alvaro Uribe.
He led protests in Cartagena against the signing of the deal.
"This gives impunity to the top leaders of FARC, the largest cocaine-trafficking cartel in the world, and makes them eligible to run for office."
The deal will only come into effect if Colombians approve it in a referendum on Sunday, 2 October.
