Winter Olympics: What are the rules of curling? How heavy are curling stones? What does sweeping do in curling?

One of the oldest winter sports still in existence, curling has become extremely popular worldwide since its Scottish early 16th century origins.

The world's oldest curling stone and and football are now kept in the same place, Stirling Smith Art Gallery and Museum, while the World Curling Federation is still based in Perth, Scotland today.

Known sometimes as the roaring game because of the noise the stones make sliding down the ice, the game was made global by Scottish immigrants settling in Canada then later in Sweden and the United States.

Today, the curling scene is dominated by Canada and Sweden, with two nations having won 10 of the last 11 Men's World Championships, while Scotland have won five since 1967.

Curling is played all over Europe and has spread to Brazil, Japan, Australia, New Zealand, China, Korea and will be competed in by 10 National Olympic Committees at Beijing 2022.

Despite its appearance at the first ever Winter Olympics in 1924, which Britain won, the sport has only been included in eight games since - returning to the official programme in 1998.

Four years later, an all-Scottish team became Britain's first gold medallists in any sport at the Winter Olympics since ice skaters Jayne Torvill and Christopher Dean in 1984.

Rhona Martin, Debbie Knox, Fiona MacDonald and Janice Rankin were subsequently given MBEs.

Scotland are the current women's European Curling champions.

The aim of curling is to score more points than your opponent. You do this by getting your stones as close to the centre of the bullseye-style target called the 'button' inside the 'house', as possible.

However, the opposing team is also aiming to do this, while knocking the other team's stones away.

Teams have four players,