The group of about 30 members, called WomenCrossDMZ, included feminist Gloria Steinem
and two Nobel Peace laureates, Mairead Maguire of Northern Ireland and Leymah Gbowee of Liberia.
On Sunday morning, a bus picked them up from the North Korean side and ferried them across the Demilitarized Zone that has separated the two Koreas for more than half a century.
"We feel very celebratory and positive that we have created a voyage across the DMZ in peace and reconciliation that was said to be impossible," Steinem said after the group, which had originally planned to walk across the zone, arrived in South Korea.
The activists said they acted as "citizen diplomats" in North Korea, speaking with women at a series of events during their time there.
"We can learn on paper and on screen," Steinem said. "But the ability to understand, not just learn, happens when we are together and able to empathize."
The group says women need to be involved in the peace-building process. It calls for reuniting families divided by the Korean War
, and replacing the 1953 armistice with a permanent peace treaty -- demands similar to those made by the North Korean
Criticism from other activists
Other activists have criticized the event
, saying the group is overlooking major problems faced by women under Kim Jong Un's authoritarian rule.
"It is absolutely outrageous that they completely ignore the suffering of the North Korean people, especially North Korean women," said Suzanne Scholte, head of the North Korea Freedom Coalition.
"If they truly cared, they would cross the China-North Korea border instead, which is actually more dangerous now than the DMZ," Scholte said ahead of the event.
North Korean women who cross into China often become victims of human trafficking, ending up being forced to work in the sex industry or sold as brides to rural Chinese men.
The reported abuses for North Korean women are not limited to the Chinese border. North Korean defectors have testified of rape and abuse in prison camps by fellow inmates or guards.
Maguire, who became known for organizing peace demonstrations during the conflict in Northern Ireland, suggested the human rights situation would improve if the two Koreas were to sign a full peace treaty.
"You can get to human rights when you have a normal situation and not a country at war," she said Sunday.
Sympathy for North Korea?
Christine Ahn, one of the event's organizers, has been called a North Korea sympathizer -- an allegation she denies.
"Basically that is a Cold War, McCarthyist mentality," she told CNN in April. "And that kind of framework has enabled Korea to remain divided. I am pro-peace. I am pro-engagement. I am pro-dialogue. I am pro-human rights."
She says she is for ending "the state of war on the Korean peninsula."
Her critics include Human Rights Foundation's Alex Gladstein, who accused Ahn of "whitewashing the North Korean regime for more than a decade, always excusing the Kims, saying they aren't so bad, and blaming North Korea's problems on South Korea and the U.S."
Observers say that a group being allowed by both North and South Korean authorities to hold this kind of event is unusual but not unheard of.
A group of bikers from New Zealand crossed the border in 2013, and another group drove through the DMZ last year.
Last week, U.N. Secretary-General Ban Ki-moon said the North Korean government abruptly canceled
his planned visit to an industrial zone. Situated to the north of the DMZ, the Kaesong Industrial Complex contains factories that are owned by South Koreans and staffed by thousands of North Koreans.