These workers must have felt on top of the world as they worked on the 123rd floor of the Lotte World Tower in Seoul during the framing completion ceremony on Tuesday.

The building, seen here from a crane, reached its final height of 550m and 123 floors when the exterior was completed. The ceremony came five years and two months after construction began.

The building's opening will likely be at the end of next year when the interior is scheduled to be completed, Yonhap news agency reported.

It will be the highest building in South Korea and fifth-highest in the world, according to Yonhap.