Museu de Marinha, Praça do Império, Santa Maria de Belém, 1400-206 Lisboa, Portugal | Under the tree in front of the Museu de Marinha coffee shop:
https://maps.app.goo.gl/CYuJhwmjjpXmFi95A
Praça do Império, Santa Maria de Belém, 1400-206 Lisboa
The tour guide will be under the big pine tree, wearing an identifying badge. You can also use the Navy Planetarium, right next door, as a reference point.