First, the Western Wall is not Judaism's holiest site. The Temple Mount, the location of the first and second temples and the holy of holies, holds that distinction. The Western Wall is the holiest site where Jewish prayer is permitted.
Haaretz has previously corrected this very same error in
twice in April 2014.
Second, the Western Wall is not a remnant of the second temple itself, but of the temple complex. It was a retaining wall of the Temple Mount, upon which the temples were located.
Third, the Western Wall is not the only remnant of the Temple Mount complex. In fact, there are many extant remains of the Temple complex. The southern, eastern and northern retaining walls are also still extant. Surviving features abutting the southern walls include a broad stairway leading up to the Temple Mount's entrance and two gates, known as the Huldah Gates, which provided access to the Temple Mount (Hershel Shanks,
Jerusalem: An Archaeological Biography, p. 143). Some of the interior part of the Herodian Double Gate (which is one of the Huldah Gates) is also still intact. There are also surviving underground remnants of the Temple complex, including the area known as Solomon's Stables. In addition, an area called "Robinson's Arch," in the south-western corner of the Temple complex, still remains. In his book, Shanks provides details concerning numerous other remnants. This, too,
Haaretz has previously corrected, in
April 2015. Other media outlets which have likewise corrected the identical error include
The Los Angeles Times and
The Associated Press.