Checkpoint Charlie was located on the border between the American and Soviet sectors of Berlin at Friedrichstraße 43-45. (The other two allied sectors being the French northern and the British center sector.)
Bond's Mercedes is coming in from Rudi-Dutschke Straße and turns right on Friedrichstraße where the allied guard house is located. They are driving past the well-known sign, stating that 'you are leaving the American sector' and in to East Berlin. The film crew could not actually film inside East Germany, so the Mercedes was only driven into No-man's land and just before the East German border, back into West Berlin after the take had been ordered 'cut' by director Glen.
"Here's the ID you'll need: Charles Morton, manufacturer representatives from Leeds, visiting furniture factories in East Germany. Carl will take you in..."
-M to Bond-
The Berlin Wall was erected in 1961 due to the fact that almost 20 % of the population in East Germany (DDR) had fled to the West. Many attempts to escape and several incidents did occur during the 28 years of separation. Throughout Berlin you can find various memorial sites over people who were killed trying to escape as well as a line through the entire city, marking the original route of the wall.
The only tribute paid to the fact that Bond was here on location in 1982 can be found in the lunch restaurant 'back-factory' on Friedrichstraße where an entire wall has been dedicated to Octopussy and Sir Roger, with a big screen TV showing the film and a model of Acrostar hanging from the ceiling. Here you can have a quick lunch with a nice view over the place that once was the center and very symbol of the Cold War.