You might have read that Coca-Cola was first served at the Olympic Games in Amsterdam in 1928. Below is a quote from a writeup in The Red Barrel magazine in February, 1929 describing how visitors to the Olympic Games in Amesterdam insteracted with the brand:
Visitors to the 1928 Games found Coca-Cola on sale at all cafes, restaurants, and small shops called “winkles” and at many kiosks outside and around the Olympic Stadium and the Rowing Course. Men wearing Coca-Cola caps and coats sold the bottled drink to the sporting crowds, while soda fountains near the entrances to the Stadium were available to those who preferred Coca-Cola in the glass. Various advertising pieces were on display, including eight Coca-Cola bulletins above each of the eight entrances to the Olympic Stadium. The Coca-Cola bottler at Amsterdam erected Coca-Cola billboards and secured Coca-Cola painted walls along the main canals and streets of the city.
Please see the photo below of one of the Coca-Cola signs above the entrances on the Coca-Cola page timeline on Facebook: Coca-Cola page timeline on Facebook, 1928