It is all too common these days to see millennials taking selfies at heritage sites on the cusp of ruin.

Photographer Sean Cham, however, has elevated the heritage selfie to an art.

In his photo project Yesteryears, the 22-year-old student went around Singapore taking posed photographs in 50 historically significant places that have been abandoned or forgotten.

The photos, which he took over a year during the heritage craze of SG50 in 2015 - Singapore's 50th year of independence - and posted on Instagram with snippets of historical information, have been collected in a book, which was released at the end of last month.

Cham, a Yale-NUS College student who is majoring in urban studies, says: "These places are vessels for history and when they are gone, so will the memories made in them. The more I worked on it, the more important I realised this project is."

He got the idea for Yesteryears in 2014, when he learnt that the Bukit Merah Housing Board block where his grandmother lived and where he had grown up would be torn down.

This spurred him to start documenting such places in Singapore - and not a moment too soon, for half of the places he photographed, including Rochor Centre, Dakota Crescent, Old Woodlands Town Centre and Pearl's Centre, have since been demolished or will soon be.

Cham, who is single, chose to place himself in the photos to give them a human focus and turn them into artistic portraits of the lives once lived there.

Often, his mise en scene includes hints of the locations of these places, which he does not name so viewers will try to discover them for themselves.

In an old barbershop in Lorong Lew Lian, for instance, he is holding a pair of durians (lew lian is Hokkien for durians), while in the hangar of Old Kallang Airport, he throws paper planes into the air.

In many of the photos, he appears multiple times. His more complicated portraits can take two or three hours to photograph, plus another hour spent stitching the images together in Photoshop.

In his most recent photo of Dakota Crescent, which was taken too recently to be in the book, he appears 58 times in different poses, a nod to the 58 years since the estate was completed in 1958.

Cham says he is no longer self- conscious of being stared at while he takes his self-portraits, although he is sometimes so excited that he forgets to be careful.

While wading through mud up to his calves in the mangrove swamp of Sungei Khatib Bongsu, one of Singapore's last undammed rivers, he realised at one point that he was standing in a pool of blood. His legs had been cut by rocks and little crabs. "I didn't feel it," he recalls. "I had this whole sense of euphoria."

He decided to compile the Yesteryears book so his project would have a more "concrete" home, instead of being lost in cyberspace. It is published by Math Paper Press.

The book resembles an old-school jotter book and contains, besides the photos, an essay by Cham on the phenomenon of the modern ruin and items such as old cinema ticket stubs, postcards and parental consent forms for school trips.

"There is a kind of amnesia Singaporeans have," he says.

"With SG50, there was a whole sense of nostalgia, but as much as people love the old, buildings keep being torn down.

"I don't think there's any way around it, but it's important that people remember these places and, in the midst of progress, we need to draw a line."

•Yesteryears by Sean Cham is available from BooksActually at $39.