When I was in Palau as a Peace Corps volunteer, many years ago, the very first archaeologist who had ever done research in Palau had left only a few months before I arrived. As far as I could tell, he never got to the monoliths, and I've never heard of any archaeologists doing research on them since. They are quite small -- only about 4 feet tall. They're truly nothing like the heads on Easter Island, there are many conflicting stories told about their origin but nothing verified. The only thing I was able to establish, after talking to the oldest Palauans in the region, was that they are very, very old -- they probably predate the first Europeans' arrival.
If you own or manage Stone Monoliths, register now for free tools to enhance your listing, attract new reviews, and respond to reviewers.