The feature will allow people to see bouts taking place from the street outside of the building, it is claimed.

Construction at the venue is due to start by the end of 2020 in a "functional" fashion, the International Sambo Federation said.

Facilities for sambo and boxing will be united by a common facade, and placed symmetrically to each other.

At the same time, visitors will not have to pass through both venues so they will be able to operate independently.

Each sport will have its own underground parking, while both training and competitions will take place inside.

"The Sambo and Boxing Center in Luzhniki will have its own 'trick' – an original architectural solution, thanks to which the actions of athletes can be observed without entering the building, from the street," said Rafik Zagrutdinov, the head of the Moscow Construction Department, to Interfax.

"Now we are carrying out design and survey work on this unique complex, and the construction of this facility is planned to begin by the end of the year."