Großes Engelsmeer, nature reserve and moor lake in Kayhauserfeld, Bad Zwischenahn, Germany

Großes Engelsmeer is a moor lake within a nature reserve near Bad Zwischenahn in Lower Saxony, surrounded by birch forest on wet high moor. The open water surface spans around two hectares and is edged with reeds and vegetation.

The Großes Engelsmeer has been a protected nature reserve since 8 January 1939, under reserve code NSG WE 068, with the Ammerland district as the responsible lower nature conservation authority. The 1.7-hectare site protects a moor lake lying in a drained high moor south of the Oldenburg–Leer railway line in the Kayhauserfeld part of Bad Zwischenahn.

The name Engelsmeer, "Engelsmeer" meaning "English lake", is the traditional name of the water in Kayhauserfeld, south of the Oldenburg–Leer railway line. The lake lies in a drained high moor, and birch woods grow around its shore. Since 8 January 1939 the 1.7-hectare area has been protected, managed by the Ammerland district nature conservation authority.

The site is open to the public year-round at no cost, best explored on foot along marked trails that circle the lake. Sturdy footwear is recommended since the ground in the moor areas can be wet and soft.

The reserve covers just 1.7 hectares and lies south of the Oldenburg–Leer railway line in the Kayhauserfeld district. It protects a moor lake set in drained raised bog, with birch woods growing around the water.