Padrão dos Descobrimentos is a monument on the northern bank of the Tagus River estuary, in the civil parish of Santa Maria de Belém, Lisbon. Located along the river where ships departed to explore and trade with India and the Orient, the monument celebrates the Portuguese Age of Discovery during the 15th and 16th centuries.

More details: https://en.wikipedia.org/wiki/Padr%C3%A3o_dos_Descobrimentos