THIRTY years of civil strife have not served as a deterrent to Cha Sim, 68, who must surely be one of the most determined stamp collectors in the world.
In 1979, Cha Sim moved to Phnom Penh from his native Takeo where he had spent the "very difficult" four years under the Khmer Rouge.
"When I moved to Phnom Penh I saw lots of stamps scattered across the boulevard in front of the Post Office," he said. "I was intrigued and I began to pick them up."
Over three decades during which Cambodia was in a constant state of civil conflict which decimated the nation's infrastructure, including the postal service, Cha Sim managed to amass a collection of some 374 different Cambodian stamps.
His collection includes stamps from as early as 1907, when the country was a French protectorate, some from the 1950s - including a batch which pay homage to the Kingdom's independence from France in 1954 - and more recent offerings, such as a stamp commemorating the first anniversary of King Sihamoni's accession to the throne in 2005.
Cha Sim has obsessively spent years and considerable sums of money buying up every Cambodian stamp he could find. "Even if you have a lot of money you can't just find these stamps in any local shop," he said.
Although Cha Sim would not part with some of his favourite stamps, he does make a small profit selling Cambodian stamps to interested foreign collectors.
He says he's bought batches of stamps for around US$30, such as a series depicting Angkor Wat, and has been able to resell them to tourists for up to $200. "I love stamps and it's nice to make a little money from them sometimes."
Cha Sim's earliest stamp is one printed in 1907. This early series of stamps incudes designs which incorporate a Cambodian ballet dancer and the Angkor Wat temple.
He also has a stamp printed in 1931 which depicts then-King Norodom Suramarit. Other stamps in his collection depict former General Lon Nol who deposed then-Prince Sihanouk in 1970.