LDS temples are typically only open to members in good standing......however, at the occasional "grand opening" of a newly-constructed temple or at the re-dedication of a restored one, the church usually has a weeks-long open house open to everybody.....for those into this sort of thing (and not LDS in good standing), it's an extremely rare chance to see the inside of a temple.....very unusual in some ways and very traditional in other ways......here are current and upcoming open houses worldwide......
https://www.churchofjesuschrist.org/temples/open-houses?lang=eng
the oldest still-operating LDS temple is in St. George, UT, and is now in a multi-year renovation....it'll be done in early 2023 and there will be a public open house, which, I presume, will be extremely popular.....
https://churchofjesuschristtemples.org/st.-george-utah-temple/