Some of the rarest things in the world

Some of the rarest things in the world range from geological features to global economic entities.

At the lowest frequency, there are 1,248 World Heritage Sites and 1,257 foreign military bases.

Active volcanoes follow closely at 1,350.

The business landscape includes 1,649 unicorn startups and 3,028 billionaires, while public companies valued at over a billion number 5,522.

Infrastructure and technology represent a larger share, with 2,301 stadiums of minimum capacity 10,000 and 7,604 skyscrapers.

The highest counts belong to naval ships at 9,931, data centres at 11,035, artificial satellites at 12,149, and nuclear warheads at 12,331.