Bacardi is dispensing frozen cocktails from an OOH-style billboard.
Passers-by will have the opportunity to sample fruity drinks made with Bacardi Coconut and Bacardi Raspberry.
The activation will be open at Observation Point, South Bank from 12pm to 7pm on 21 and 22 August.
After sampling the serves, attendees can vote for their favourite for the chance to win one of 10 frozen cocktail kits in the flavour of their choice.
The kits, created in collaboration with Poptails by Lapp, are also available for purchase online. There is a Bacardi Coconut Rumstar Colada kit with Passion Poptails, and a Bacardi Raspberry Red Berry Daiquiri kit with Berry Poptails.
Marie Peyto, brand director for Bacardi Rum UK, said: "With many Brits staycationing in the UK this summer, August will finally bring us some much-deserved heat and how better to celebrate than with a frozen cocktail.
"After partnering with key bars across the UK to bring delicious frozen cocktails to the public, we wanted to create a way for people to also enjoy at home with Bacardi Rum just in time for summer's hot finale.
"Now anyone can create bar-quality frozen drinks in their own kitchen with our new Fruity Frozen Cocktail Kits in partnership with Lapp – complete with new eye-catching Bacardi Coconut and Raspberry bottles that are perfect for summer entertaining."