The Presidio at Ushuaia is known as "the jail at the end of the world". We can find it in "bahia Golondrina" and now its visited as a museum. From 1902 to 1947 this jail held some of the most wanted outlaws in South America. Another visit you have to do is the Train at the end of the World that goes thru woods, mountains, rivers and valleys.
Because of weather conditions the summer is the ideal time of the year to be at Ushuaia. You can take trips thru the Beagle channel (observing sea wolves and Magallanes penguins at Cape Horn) or you can take cruises that include all of the "Atlantida Argentina". There is a good possibility that you might want to try one of the many extreme adventures offered here (trekking, horse rides, mountain bike, sport fishing, etc.)
Nightlife at Ushuaia is prepared to meet many types of fun. The length of San Martin Avenue holds restaurants, shops as well as very peculiar pubs and teahouses. After tasting some of the food specialties in the area (thornback crab, shellfish, fire lamb, etc.) many take a trip to one of the six Casinos in town holding Black Jack and crabs tables.