Marcobrunn, Spring and vineyard location in Eltville am Rhein, Germany

Marcobrunn is a 6.7-hectare vineyard site on the Strahlenberg between Hattenheim and Erbach, named after a spring enclosed in neoclassical form around 1810. The site slopes about 5° to the south and grows only Riesling on deep, calcareous, clayey marl. The spring stands at the old boundary between the Erbach and Hattenheim districts.

The name Marcobrunn derives from Old High German 'marka', meaning boundary, because the spring marked the border between Erbach and Hattenheim. The site grew in importance over centuries as both communities relied on the water source for their vineyards.

The name likely comes from Old High German 'marka' (boundary), as the spring stood on the Erbach–Hattenheim line; another reading links it to Saint Mark, patron of Erbach's church, attested in 1258. The present neoclassical stone basin was built by Erbach citizens in 1810 and renovated in June 2014, though it was vandalised with graffiti before the unveiling.

The site is best reached on foot along a path through the vineyard region, making a visit accessible without special equipment. The terrain can be explored in most weather conditions, though sturdy footwear is recommended due to the slope.

Goethe passed the Marcobrunn by carriage in 1814, and Thomas Jefferson had ridden past in 1788. In 1883, a 1868 Erbacher Marcobrunn Cabinet Beerenauslese from the Schönborn estate was poured for Kaiser Wilhelm I at the inauguration of the Niederwald monument, but only after being relabelled as an "1868 Rüdesheimer", which was then still permitted.