A twentieth-century casino hotel built by unknown aliens on Theta VIII from a pulp novel, as a home for the surviving astronaut of a lost NASA ship.
The Hotel Royale is the setting of the Next Generation episode The Royale.
Investigating wreckage in orbit of Theta VIII, the Enterprise-D finds a revolving door standing in a pocket of breathable air on a poisonous world. Riker, Data and Worf pass through into a hotel and casino full of people who cannot see beyond it, and find they cannot leave.
In a bedroom they discover the remains of Colonel Stephen Richey of the NASA ship Charybdis. His diary explains that aliens accidentally killed his crew and built the hotel from a novel aboard, taking it for a guide to human life. The away team escapes by acting out the book's ending, with Data breaking the bank at the craps table.