Building frozen castles at China's Harbin Ice Festival

The 37th Harbin International Ice and Snow Sculpture Festival in China has opened to visitors, featuring frozen towers, palaces and castles.

The festival in Harbin, a city in China's north-east Heilongjiang province, is one of the biggest of its kind.

It features towering ice and snow structures, and will host activities like sledging, ice hockey, ice football, speed skating and Alpine skiing competitions.

With entry to China restricted due because of the coronavirus pandemic, domestic tourists are expected to make up the majority of visitors.

The festival began in 1963 and was interrupted during China's Cultural Revolution, resuming again in 1985.

In December, about 300 "ice miners", many of whom are construction labourers and farmers, built the festival's towering ice structures.

To build the frozen city, tens of thousands of ice blocks were prised out of the kilometre-wide frozen river Songhua, which winds its way through Harbin.

The blocks were then moved by truck to the festival venue, where they were used to build life-sized castles, pagodas, bridges and even a functioning hotpot restaurant.

Ice miner Wang Qiusheng told Reuters news agency why they needed to use ice from the river: "Artificial ice isn't that thick, and isn't strong enough to stand in the wind."

The workers wore knee-high rubber boots, down jackets, thick gloves and hats with flaps to protect their ears from the freezing temperatures.

"We come to mine ice at 6am every day," Zhang Wei said to Reuters.

"We need to work overtime sometimes, until 8 or 9pm, even late after midnight."

The ice blocks were laid on top of one another to build walls.

The workers then shaped, trimmed and cut them to size with chainsaws, pickle forks and tooth chisels.

When working, the ice miners ate their lunch - a bowl of piping-hot noodles, dumplings or steamed buns - in makeshift canteens made of wooden poles and plastic sheets.

The elaborate ice structures are lit up at night in a splendid array of colours.

Harbin Ice Festival runs until 25 February 2021.