Castle Falkenstein is a steampunk-themed fantasy role-playing game

Designed by Mike Pondsmith and originally published by R. Talsorian Games in 1994. The game is named for a legendary unbuilt castle in the Bavarian Alps. 

The game is set in the alternate reality of New Europa, where the forces of magic and technology have merged. Players take on the roles of gallant adventurers who embark on quests of intrigue and derring-do in the spirit of Victorian adventures such as The Prisoner of Zenda.

Castle Falkenstein is known for its unique setting, combining elements of alternate history, Celtic mythology, steampunk, and a whimsical, fairy-tale feel. The game system is also somewhat different from many other RPGs, being heavily geared towards roleplaying and storytelling over game mechanics and numbers.  

If you're interested in a unique and immersive role-playing experience with a touch of steampunk and fantasy, Castle Falkenstein is definitely worth checking out.