  We present a new abundance analysis of the intermediate age Galactic open
cluster NGC 3680, based on high resolution, high signal-to-noise VLT/UVES
spectroscopic data. Several element abundances are presented for this cluster
for the first time, but most notably we derive abundances for the light and
heavy s-process elements Y, Ba, La, and Nd. The serendipitous measurement of
the rare-earth r-process element Gd is also reported. This cluster exhibits a
significant enhancement of Na in giants as compared to dwarfs, which may be a
proxy for an O to Na anti-correlation as observed in Galactic globular clusters
but not open clusters. We also observe a step-like enhancement of heavy
s-process elements towards higher atomic number, contrary to expectations from
AGB nucleosynthesis models, suggesting that the r-process played a significant
role in the generation of both La and Nd in this cluster
