The Western Wall is open 24/7/365. It is the western wall of the Temple Mount where the first and second holy temples stood together for 830 years.
11 million visitors come to the wall annually making it the number 1 tourist spot in Israel. It’s obviously the number 1 prayer spot. For comparison sake, The Eiffel Tower gets 7 million visitors a year.
The Western Wall was off limits to Jews for 19 years from 1948 to 1967.
There are 45 layers of stones laying one on top of the other that make the wall. 28 of the rows are above ground and 17 are below ground level presently.
Before 1948 Jews were only permitted to pray in a narrow swath of land opposite the wall 3.5 meters wide. Today the Western Wall plaza can hold tens of thousands and praying is a pleasant experience instead of being in the narrow confining place available before 1948.
After conquering Jerusalem King David bought the land including Mount Moriah which would end up being the Temple Mount from Aravnah the Jebusite. This took place about 2,800 years ago.
The Temple Mount is the place where Abraham bound Isaac as an offering to G-d. It is also the place where Jacob dreamt his dream with the ladder going up to heaven with angels going up and down in which G-d promises to watch over him.
The largest stone used for building the Western Wall is 13.6 meters long and 3.3 meters deep. It weighs approximately 570 tons. It is the largest stone in any construction in Israel. For comparison, the pyramids stones were from 2.5 tons to 15 tons and the largest stone was a floor foundation stone 8 x 6 x 2.5 meters which is still considerably smaller than the largest Western Wall stone. The average dimensions of other stones in the Western Wall were 1 meter high and 3 meters long, but some stones were as long as 12 m.
The Western Wall is most crowded on the Ninth of Av when we mourn the destruction of both of our holy Temples. During Passover and Sukkot the day the Cohanim (priests) bless the nation with the priestly blessing has tens of thousands of people getting blessed and today, Jerusalem Liberation Day when the old city was liberated and Jerusalem became unified in Jewish hands as it was for thousands of years.
If you pray at the wall 40 days straight tradition has it that your prayer will be answered.