This so-called 'Gold from the Baltic' was prized by Polish kings, whose residence was the Royal Castle of Krakow, for its versatility and beauty. Baltic amber is fossilized resin that was washed down ancient rivers from prehistoric forests in the whereabouts of today's Scandinavia. There are major deposits out at sea, and the bustling Baltic port of Gdansk has played a key role in the big business crafting of amber in Poland since medieval times.