Jaffna or the City of Jaffna is the capital city of the Northern Province of Sri Lanka.The city is surrounded by Jaffna Lagoon to its west and south, Kokkuvil and Thirunelveli to the north, and Nallur to the east. Jaffna peninsula is made of limestone as it was submerged under sea during the Miocene period. The limestone is gray, yellow and white porous type. The entire land mass is flat and lies at sea level. Within one mile of the city center is the island of Mandativu which is connected by a causeway. Palmyrah groves can be seen where land has not been used for construction. Other notable vegetation is a leafless shrub called talai (alae africana) and koddanai.