Like this naked youths group sculpture below, dated 1st century AD which was found in Rome, and recorded in the Ludovisi collection. It then went into the collection of the Queen Christina of Sweden, then kept until 1839 in a Spanish palace (San Ildefonso) before to be displayed in the Prado Museum in Madrid.
Opposing each other in several aspects, they formed the Gemini (Twins, in Latin) constellation. The myth of Castor & Pollux is more complex, I suggest you read some of the Sources.
A dozen sculpture copies have been done in marble, bronze or even cast iron, by various sculptors, in Germany, UK, France, either identical, using cast from plaster, or sometimes in different size, or even giving themselves some freedom from the original. See the list in the Wikipedia source.
The French copy, seen below, was achieved, after almost 25 years of work, by the sculptor Antoine Coysevox, visible since 1712 in the Château de Versailles, near Paris.
The UK marble copy was sculpted in 1767 by Joseph Nollekens (1737-1823), who went to Rome and may have seen the plaster copy kept at the French Academy there. The sculpture is located in the Victoria and Albert Museum in London.
In Germany, a bronze copy is in Berlin, Charlottenburg, cated by Christoph Heinrich Fischer in 1833.
Still in Germany, Goethe ordered a plaster cast for his house in 1812, and in a letter he sent to a friend, mentioned that 'These two ephebs have always been most pleasing to me'.
And more recently, in 1995, a wonderful sculpted glass by Wolfram Ames has taken place among the private collection of Othmar Rahm in Bonn.
The Rameau opera Castor & Pollux, in his edition of Harmonia Mundi / Les Arts Florissants / William Christie is here illustrated with the Poussin drawing of 1628 made with pen and brown wash.
Andrej Koymaski website
Château de Versailles