FancyMancy said:
Are you referring to
Astral Temples?
He is basically referring to a semi pop culture phenomena, where people make a mental image of a "place" to store their memories and better recall them. I've attempted using my Astral Temple for this before and it only sort of worked, doing general cleaning and chakra worked had far more results for memory improvement, along with mercury squares which have done more than any of that before.
It's become popularized due to certain depictions in media, tv and movies mostly in west, of super "smart" characters using them. Personally I think just doing Mercury squares for better memory would be a better use of time, The Mind Palace technique seems to have some reported use by others, but you need really good visualization to start with.