Dotted across London, national hospitality houses offer a base for a country's athletes, officials and occasional celebrities. Some are open to the public, showing a festive side to tourists from around the world. Others are strictly invitation only, like the American pavilion at the Royal College of Art.
Here's an eclectic, unscientific guided tour:
RUSSIA: 2014 IS OURS
Russia, home to the 2014 Winter Games in Sochi, has pulled out all the stops with two open-air attractions, Russia Park and Sochi Park, set in London's Kensington Gardens.
Russia Park is a vast sea of Astroturf dotted with bean bags, ping pong, chess and mini-golf. Medal winners and artists share the stage, with entertainment ranging from Central Asian throat singers to jazz bands to mini-rock festivals.
SAMBA, BABY
Brazil, home to the 2016 Rio de Janeiro Games, has transformed Somerset House, a sprawling edifice beside the River Thames, into Casa Brasil.
The courtyard has been taken over by Brazilian bands, including Sargento Pimenta (Portuguese for Sgt. Pepper) a popular Carnival ensemble that takes a samba approach to Beatles classics. The bar serves up a mean caipirinha, a popular Brazilian cocktail. There's also a "3-D paragliding experience" and extensive exhibitions of Brazilian art and design — much of it bold, confident and playful.
SMALL IS BEAUTIFUL
Denmark has turned a yacht-fringed marina, St. Katharine Docks, into a little corner of Scandinavia. There is music, hotdogs and beer, Scandinavian designs, a Viking ship, meaty food and big screens showing Olympic highlights including handball — a Scandinavian obsession.
ALPINE TREATS
Nearby Austria House offersbratwurst with sauerkraut and Stiegl beer on a ski chalet-style terrace with views of the Tower of London, as well as big-screen sports and a "yodeling telephone box."