腐沼(Palus Putredinus)，又译“凋沼”，是月球上的一座月海，属于雨海的一部分，直径约161公里。它从阿基米德陨石坑（Archimedes）的东南方延伸到位于雨海边缘崎岖的亚平宁山脉。它的名称源于拉丁语"Palus Putredinis"，意为“腐烂沼泽”。该区域由于被岩浆覆盖而近乎平坦；"奥托利克斯环形山"(Autolycus)和阿基米德山脉(Montes Archimedes)分别构成了它的北侧和西侧边界。

该区域南部是一组被称为"阿基米德月溪"(Rimae Archimedes)的溪谷系统，南面是一条显目的称为“布拉德利月溪"(Rima Bradley)的线型溪谷；东面是“哈德利月溪”(Rima Hadley)。而"菲涅耳月溪"(Rimae Fresnel)曾作为阿波罗15号的着陆点。正对着腐沼中心点西北方的是几乎消失的斯帕环形山，月球2号就坠毁在该区域。

Palus Putredinus (latin for "Marsh of Decay") is an area of the lunar surface that stretches from the crater Archimedes southeast toward the rugged Montes Apenninus range located on the southeastern edge of Mare Imbrium. This region is a nearly level, lava-flooded plain bounded by the crater Autolycus to the north and the foothills of the Montes Archimedes to the west. The selenographic coordinates are 26.5° N, 0.4° E, and it lies within a diameter of 161 km.