The structure in water of two cyclic hexapeptides is determined. The locally enhanced sampling method that we developed is employed. Within the accuracy of the model the peptide CAAAAC does not have a unique structure while CHDLFC does. The driving force to structure in CHDLFC is the hydrophobic interaction between the phenylalanine and leucine. The implications of our results to short-range nucleation sites in protein folding are discussed.