Gan Aden is here and now its only absent in our minds. Gan Aden is another dimension that we can only reach in our minds where G-d’s most holy place is our body’s Temple.
Sages tell when we read about Jacob’s dream of the latter the malachim which translates as messengers which were described as going up and down is G-d’s people going to a higher place to bring G-d’s Holiness His Kingdom to earth that is why we do not read the messengers were coming down and going up because malachim going down and going up would be angels instead. In this dream the malachim are G-d’s people and not angels.
The question we have to ask is why is G-d’s people His messengers going up and down? Because. It is our task as His people to build Hashem’s Kingdom here to match what is higher so this brings Moshiach and this will bring Gan Aden back as well.We would know the Kingdom has arrived and the Garden is once again established when our nostrils are tickled with the fragrance of the Ketoret.