The fifteenth issue of the collector-investment series of platinum coins that pays tribute to the Czech monuments listed by UNESCO, is dedicated to the Spa Triangle. It shares the listing with other famous spa towns in Europe - Belgium, France, Italy, Germany, Austria and Great Britain.

The so-called spa triangle consists of three towns located in the westernmost part of Bohemia - Karlovy Vary, Mariánské Lázně and Františkovy Lázně. These international resorts are an exceptional example of the European spa phenomenon that flourished from the early 18th to the mid-20th century. Spa culture, which combines the healing power of nature with exceptional architecture, brought a new perspective on medicine and leisure. Bringing together people from all over the world, spa towns had an enormous influence on the democratisation of European society.

"Mariánské Lázně is symbolised by the Colonnade of Caroline's Spring, Karlovy Vary is represented by the Market Colonnade and Františkovy Lázně is represented by the famous statue of the naked boy František," describes the reverse side of the coin made by medal maker Lenka Nebeská, DiS. All three motifs are connected by a triangle, the vertices of which refer to the location of the spa towns on the map. The perimeter of the reverse side is surrounded by a pearl ornament with the inscription  LÁZEŇSKÝ TROJÚHELNÍK (SPA TRIANGLE). The obverse side of the coin, which is common to the entire platinum series, bears a collage of architectural elements from various Czech buildings inscribed on the UNESCO World Heritage List. As the coins of the Czech Mint are issued with the licence of a foreign issuer, which is the island of Niue, the obverse side bears its necessary attributes - the nominal value of 50 DOLLARS (NZD), the name and portrait of Queen Elizabeth II and the year of issue 2022.

A special certificate of authenticity is an integral part of the coin which is issued in a mintage of only 100 pieces.

At the time the platinum series began to be issued, twelve tangible monuments were listed by UNESCO. This prestigious list was expanded to include four more Czech sites in 2019 and 2021. These also appear on the coins, but unfortunately they do not fit into the wooden collector's case that was created in 2017.