Thank you... I was looking for this thread!
We docked at the Port of Monte Carlo, pier name Cambiasso & Risso 7 on Rue du Gabian.
dispiller, we did a ship tour so got on a bus at the pier, yet getting into Monte Carlo is walkable if you're in good shape. There's a boardwalk along the water's edge that we enjoyed. Just know that once you cross the street into the city, there are steep hills, as well as sharp curves that drivers tend to speed around, so be careful. There are also elevators that take you up to the Palace.