Ledra Street has become the sixth crossing on the island to open since April 2003, when Turkish Cypriots for the first time lifted entry curbs for Greek Cypriots.
Tim Friend, reporting for Al Jazeera from Nicosia, said the opening of the Ledra Street crossing signalled "renewed optimism" for reunification in divided Cyprus.
"Its now felt the impetus is there on both sides of the border - from the Turkish Cypriot leaders and from the Greek Cypriot president as well," he said.
Only a 70-metre stretch of Ledra Street is in the 300km UN buffer-zone, the Green Line, which partitions the island.
"Its an extraordinary moment," Friend said.
"It's not much in terms of distance but it means an awful lot in terms of history."
The opening coincides with a three-day visit by Lynn Pascoe, head of the UN department of political affairs, to advance reunification efforts.
|Security was tight at the crossing, the |
sixth to reopen since 2003 [AFP]
"There is a very positive tone here in Cyprus at the moment and a palpable sense of momentum," Pascoe said on Wednesday.
"I think Cypriots are right to have high expectations. I'm encouraged and I will pass this on to the [UN] secretary general [Ban Ki-moon] when I talk with him."
Demetris Christofias, Cyprus's newly elected president, and Mehmet Ali Talat, the Turkish Cypriot leader, agreed in March to open the crossing, reviving hopes of an overall peace deal.
As part of his visit, Pascoe has held talks with both the Greek and Turkish Cypriot leaders.
Hasan Ercakica, a spokesman for Talat, described the meeting as productive.
He said Pascoe had "seized the chance to acquire information regarding the way the Turkish Cypriot side considers the issue".
Cyprus has been divided along ethnic lines since 1974, when Turkey seized its northern third in response to an Athens-engineered Greek Cypriot coup in Nicosia aimed at uniting the island with Greece.
A UN plan to reunite the island failed in 2004 when the Greek Cypriots voted against it in a referendum, although the Turkish Cypriots voted overwhelmingly in favour.
Ledra Street, known in Turkish as Lokmaci Street, is at the heart of Nicosia's old commercial district.
It was a popular shopping thoroughfare in the past, and remains a popular promenade for families and tourists.