The battle of the River Plate was the first naval battle of WWII.
It could perfectly be watched from the coasts of Punta del Este, where today at the port are two big commemorative plaques.
My grandma, who lived big part of her life in Punta (moved there in 1951) told me she heard the cannons from Montevideo. And the day after went to the port to see the Graf Spee.
It is an interest story. Lots of the sailors stayed in Montevideo and BsAs to live forever, some still alive. Wrong, the last one died in 2013 at age 93.