Pico dos Três Estados is a mountain peak at which the three Brazilian states of Minas Gerais, Rio de Janeiro, and São Paulo all meet, respectively in the municipalities of Passa Quatro, Resende and Queluz.
At an altitude of 2,665 metres, the peak is located within the Mantiqueira Mountains near Pedra da Mina and Pico das Agulhas Negras. At the exact point where the three borders meet, there is an iron tripod with the names of each state.
Wikipedia https://en.wikipedia.org/wiki/Pico_dos_Três_Estados
Address Brazil
Coordinates -22°24'22.551" N -44°48'32.722" E