Forest Spring, Natural spring in Mariánské Lázně, Czech Republic.

Forest Spring (Lesní pramen) is an iron-rich mineral spring in the spa park by Třebízský stream in northern Mariánské Lázně. Its water emerges at about 7.6 °C and differs in composition from the town's other springs. The spring is covered by a classicist pavilion rebuilt by Friedrich Zickler in 1869.

The spring was already known in 1683 as Schneidsaeuerling and was named Lesní pramen around 1828. It was captured in 1827 and covered by a wooden pavilion in 1830; in 1840 Abbot Melchior Mahr replaced it with a circular temple of 16 Corinthian columns. The present classicist pavilion was built by Friedrich Zickler in 1869.

The spring's name, Lesní pramen (Waldquelle in German), was adopted around 1828. Nearby stands a 1975 bronze group of Goethe and the Muse by German sculptor Heinrich Drake, and a memorial stone to writer Václav Beneš Třebízský, who spent his last days in the town in 1884. A music pavilion hosts local orchestras in summer.

Visitors can reach the spring by following marked pathways through the spa park, which also connects to other mineral sources and recreational areas. The location offers easy access and connects well with other park attractions.

The spring's pavilion has been a protected cultural monument of the Czech Republic. The water emerges at about 7.6 °C and differs markedly in composition from the town's other springs; it was often flavoured with lemon juice or diluted with whey.