Baltrum is a barrier island off the coast of East Frisia (German:Ostfriesland), in Germany, and is a municipality in the district of Aurich, Lower Saxony. It is located in-between the chain of the seven inhabited East Frisian Islands. Baltrum is the smallest island in this chain by area and inhabitants. It has a land area of 6.5 square kilometres, and a population in (2011) of just over 500 resident inhabitants.