SOCHI, Russia — The first few days of training on the slopestyle course at the Sochi Olympics did not go smoothly.

Two snowboarders crashed and were carried away on stretchers as much of the field grumbled about treacherous rails and jumps with too much boost. Officials found themselves scrambling to quell a growing storm.

“Just some small adjustments,” course designer Anders Forsell said.

The slopestyle controversy earlier this week represented a rare bump for Sochi, whose venues have otherwise received glowing reviews.

By most accounts, the Russians have succeeded in building a collection of world-class venues ranging from a glittering ice dome on the coast to a highly technical bobsled run in the nearby mountains.

Even the scenery has impressed.

“It is insane,” U.S. snowboarder Sage Kotsenburg said. “It’s one of the most beautiful places I’ve ever been.”

Hockey, curling and skating will take place near the city, in a “coastal cluster” of five arenas that form a tight circle around Fisht Olympic Stadium, where the opening ceremony will be held Friday evening.

Skiers, snowboarders and sliders will compete about 30 miles to the north in the “mountain cluster,” with its five venues carved into the slopes of the Caucasus range.

The International Olympic Committee is promoting Sochi as one of the most modern Olympics yet.

“It will be a great Games for the athletes,” IOC President Thomas Bach said upon arriving in Russia last week. “They will have state-of-the-art sports facilities.”

Bolshoy Ice Dome: The word “Bolshoy” means “big” in Russian and, with a capacity of 12,000, this represents the larger of two arenas devoted to hockey along the Black Sea.

Figure skaters like to land their jumps on soft ice; the short-trackers want the surface harder and faster. “But we’re prepared for anything they throw at us,” American racer J.R. Celski said.