MSPeconomist

There's a relatively unknown design museum.

Orchid gardens.

The public library, for architecture and views. It's about five blocks from Raffles Hotel and was first opened when Queen Elizabeth II visited Singapore about a dozen years ago. Sometimes there are special exhibits.

Singapore Management University for architecture. There's a small art gallery in the social science building that's sometimes open for special exhibits. It's a new campus in the CBD, basically across the street from the art museum. It has a bunch of services underground, beside the subway station that was built for the university. [By contrast, the older and traditionally prestigious Singapore National University is located in the suburbs.]

Malaysian Cultural Center (name?) sometimes has special events.

Various temples. Just walk around to find the less known ones.

I've enjoyed walking around in the embassy area beyond the far end of Orchard Road. There's some interesting architecture.

Don't forget the annex to the art museum.

Explore the quiet far end of the river. There are walking paths on both sides and the river shuttles serve this area too. There's a big ordinary shopping mall around this area too, which is quite a contrast from the fancy ones in MBS, along Orchard Road, near Suntec City, in Raffles Center, etc.Unfortunately it's not well served by the subway system.

For people watching and some architecture (not as good as elsewhere in the city, such as MBS and the public library), walk on some of the fancy residential streets behind and up the hill from the St Regis. You'll see maids walking children and lots of people walking dogs (which are prohibited in public housing in Singapore).