The Pannonian Sea was a shallow ancient sea, where the Pannonian Basin in Central Europe is now. During its history it lost its connections with the neighbouring seas and became a lake. The Pannonian Sea existed from about 10 Ma (million years ago) until 1 Ma, during the Miocene and Pliocene epochs, when marine sediments were deposited to a depth of 3–4 km (1.9–2.5 mi) in the Pannonian Basin.