Neuer Grumbacher Teich, Water reservoir in Goslar, Germany.

Neuer Grumbacher Teich sits behind an earthen dam in the forested highlands above Goslar, holding dark water surrounded by spruce and beech trees. The reservoir basin stretches between gentle slopes, with its surface reflecting the surrounding woodland canopy throughout the year.

The pond's construction date is uncertain: the 'Neue Bauart' dam type was only introduced in 1714, so it must postdate that, yet older records exist in the Lower Saxony mining archive. A major building phase took place in 1733, when poor workmanship led to the site managers being jailed for up to three days on bread and water. The dam was raised in 1974, 2001 and 2011, and the bottom outlet was renovated in 1982.

Locals call it the "Fünfter Teich" (Fifth Pond), counting upstream from Bockswiese. The dam carries a bench of the Liebesbankweg, a themed hiking trail that passes close by. Because the pond supplies drinking water for Hahnenklee-Bockswiese, swimming and fishing are not allowed.

Hiking trails lead through the forest to the dam and along the shore, with the climb from the valley taking roughly an hour. Sturdy footwear helps on sections that can become slippery after rain, especially where roots cross the path.

The dam is an earth-and-rock fill structure never mechanically compacted, which is why it still settles a few millimetres each year after three centuries. The wooden slide beside the footbridge over the spillway is a Schussrinne, built to carry floodwater downhill without damage.