H.P. Lovecraft 
The Shadow Out of Time 

A novel told in first person by a human abducted mind, describing the world of the ancient alien strange civilization, a world of amazing colossal partial underground costructions that persisted buried for eons. The Shadow Out of Time is the story of Professor of Economics Nathaniel Wingate Peaslee who faints one day in the middle of a lecture and regains consciousness five years later only to find that he–or some entity inhabiting his body–has been pursuing eccentric researches in the obscure libraries and remote places of the world. The Nathaniel of those five years acted strange, knew foreign and dead languages, travelled to weirdest places, researched the strangest things and talked to various cult leaders. Eventually his journey ends in the outback of Australia, amid cavernous ruins and terrifying revelations.