There are numerous observances which we have to remember that the Beis Hamikdash has still not been rebuilt.
These include:
At a Chasuna (wedding) we (discreetly) place ash on the Chasan’s head in fulfillment of the verse that we should remember Jerusalem even at the time of our greatest joy.
Likewise, at a Chasuna, when the Chupah ceremony is completed, we have the Chassan break a glass to remember the loss of the Beis Hamikdash.
When a person sees the place of the ruins of the Beis Hamikdash, they should recite “Boruch Dayan Hoemes” (Blessed in the true judge), without saying Hashem’s Name as we do by current mourning of a passed relative. Then, while standing, they should tear the garment that they are wearing.

Good morning Rabbi Rhine,
With my daughters going to Israel what is the correct thing to do in regards to tearing kriyah when seeing the kotel for the first time?
I have heard that there are opinions saying yes and others saying no.
Rabbi Rhine’s reply:
We recommend:
Put on a shirt above the regular clothing, and when you get to visual of Kotel/ Beis Hamikdash in ruins, while standing, with scissors start tear at top (near neck) of shirt through seam (can do this pilot scissor part of tear at home, too). Then recite “Boruch Dayan Hoemes” (not with Hashem’s Name), then rip 4 inches down into garment. Torn shirt may be removed after a moment, if you choose, even as still at Kotel, as mitzvas kriya has been done.
(Some seminaries arrange to go on Erev Shabbos, at a time that you don’t have to tear. Others may absolve girls because of tzniyus, but the extra shirt method solves this.)
Besuros Tovos, Have a wonderful trip!