Mangadu is a megalithic site situated 8 kms. north-east of Kollam town. The site is located very near to 'Madan kavu', a small traditional temple. This urn burial site is demarcated on the surface with uneven blocks of laterite with an area of approximately 10 x 10 meters. The stone blocks form three circles and are in slanting position.Madan Kavu was excavated by the Department of Archaeology in 1991 and the findings revealed the long Iron age in kerala is datable to the begining of the first millennium B.C. Now the site is declared as protected area under the Archaeological monuments sites and remains act.