The Sinaia Casino is one of Romania's finest Belle Époque buildings, an extravagant confection of towers and arcaded terraces that commands the central park. Built in 1912–1913 at the initiative of King Carol I and designed by architect Petre Antonescu, it was intended as the social heart of the royal resort — a place for concerts, balls, and the kinds of entertainment that aristocrats and wealthy Bucharest families expected when summering in the mountains.
The casino no longer operates as a gambling venue and has gone through various uses over the decades; it now functions as a cultural events centre. The interior, with its ballroom, frescoed ceilings, and ornate woodwork, is worth seeing if tours are running. The building rewards attention from outside too: the formal terraces, the ornamental ironwork, and the ensemble with the park and hotel facades behind it show how deliberately Sinaia was planned as a European-style resort.
Parcul Dimitrie Ghica in front of the casino is pleasant for a walk and gives good views of the facade. Outdoor concerts are sometimes held on the terrace in summer.