Syndle is a lake in the municipality of Grimstad in Aust-Agder county, Norway. It's located about 5 kilometres (3.1 mi) northwest of the city center of Grimstad, in the Landvik area. Syndle has an area of about 6 square kilometres (2.3 sq mi) and flows into a small river on the northeast part of the lake which connects it to the neighboring lake Rore which eventually flows into the Nidelva river.