U-series analyses have been made of travertine samples from the archaeological site at Ehringsdorf-Weimar. The lower Travertine, in which hominid remains were found, yields apparent ages from >350,000 to 200,000 yr. Correlation between isotope ratios yields an age of about 230,000 yr. One sample of the upper Travertine gives and age of 111,000 ± 47,000 yr. Both upper and lower travertines contain fauna and flora indicative of interglacial conditions. The lower Travertine was deposited during isotope stage 7, while the upper Travertine may have been formed during isotope stage 5. This contradicts most earlier biostratigraphic studies which assigned both lower and upper Travertines to stages of the Eem interglaciation (correlative with isotope stage 5). The fauna and flora of the lower Travertine are significantly different from those of the upper Travertine, however, and in some respects are transitional to those of the travertines of Bilzingsleben, which appear to be older yet.