And the pillars of Enoch are written of by several ancient authors. Here's one from Josephus that tells of them being hidden before the flood:
The children of Seth "also were the inventors of that peculiar sort of wisdom which is concerned with the heavenly bodies, and their order. And that their inventions might not be lost before they were sufficiently known, upon Adam's prediction that the world was to be destroyed at one time by the force of fire, and at another time by the violence and quantity of water, they made two pillars, the one of brick, the other of stone: they inscribed their discoveries on them both, that in case the pillar of brick should be destroyed by the flood, the pillar of stone might remain, and exhibit those discoveries to mankind; and also inform them that there was another pillar of brick erected by them. Now this remains in the land of Siriad to this day."
- Flavius Josephus, Antiquities of the Jews Bk I, Ch II, Sn 3
Here is a link to her website
Her work in recovering the religious practices of ancient Israel is quite interesting. She also has a lot of eye opening things to say about what was going on in Israel around the time of Lehi's exodus. Most of her work is totally independent of any LDS influence. It wasn't until after she had written several books on the subject that she was contacted by LDS scholars who were interested in her work. She was quite surprised to find out what the scriptures of the restoration had to say and how closely LDS theology supported her theories.
Here is a link to an MP3 of a lecture she gave at BYU in May of 2003.
What Did Josiah Reform? The Earlier Religion of Israel
She was also a respondent at the Worlds of Joseph Smith conference that was held at the Library of Congress during June of 2005 commemorating the anniversary of the prophets 200th birthday.
Session 2: Joseph Smith and the Recovery of Past Worlds
There is also a paper at FARMS discussing her work.
Paradigms Regained: A Survey of Margaret Barkers Scholarship and it's Significance for Mormon Studies