MACAU — What will become of Lady Luck?

In 2015, officials in Macau announced that they planned to redevelop the 1962 Hotel Estoril, the former Portuguese colony’s first modern-style casino resort, which features a mosaic on its concrete facade depicting Fortuna, the Roman goddess of chance.

But the redevelopment plan has been stalled for two years, mostly because of opposition from young activists. And the fate of the hotel has prompted an unusually acrimonious debate over which sites best represent Macau’s history and identity — and which are worth preserving amid a recent flurry of urban redevelopment projects.

“There’s a general sentiment that Macau has changed too fast in the past 10, 15 years,” a period in which the construction of several enormous casino resorts has transformed the city’s skyline and character, said Sulu Sou, 26, the vice president of the New Macau Association, one of the civic groups that is fighting to save the Estoril and its mosaic.

The Estoril and other unprotected sites that face redevelopment in Macau “were very important in our childhood,” Mr. Sou added. “And that’s why a lot of young people feel a sense of urgency about them being lost.”