collocations - Can I say 'I swam at the beach'?

I have come across the following sentence in New Round-Up 3 Pearson Education Limited 2010:

I swam at the beach last weekend.

I would have understood if it were 'at the seaside', but 'at the beach' strikes me as unusual.

Answer

At least to this American, "the seaside" seems too general for the specific action of "I swam". I generally think of "seaside" as referring to a coastal area in general, though perhaps this because (at least Merriam-Websters EL definition of seaside seems to think this) in AmE seaside is most often used as an adjective (e.g. the seaside town, a seaside hotel) rather than referring to the actual coast/strip of sand where one might swim. Additionally, the word seaside to me could be connoting any portion of the coast, whereas one primarily swims at specific sandy places: the beach.