The Royal Palace is a complex of building which serves as the royal residence of the king of Cambodia. The Kings of Cambodia have occupied it since it was built in the 1860s, with a period of absence when the country came into turmoil during and after the reign of the Khmer Rouge. The palace was constructed between 1866 and 1870.

The Royal Palace and the famous Silver Pagoda, lined with a tiled floor of 5,000 silver tablets. The Silver Pagoda, originally built in 1892, was largely spared sacking by the Khmer Rouge and houses a revered ‘Emerald Buddha’ – akin to the Emerald Buddha held in Bangkok’s Grand Palace – as well as a ‘Golden Buddha’ encrusted with more than 9,000 diamonds.

The National Museum of Cambodia is Cambodia's largest museum of cultural history and is the country's leading historical and archaeological museum. It an appreciation of the splendour of Khmer history and art. Many of the sculptures there were made before construction of the Angkor ruins began. The museum houses one of the world's largest collections of Khmer art, including sculptural, Khmer ceramics, bronzes, and ethnographic objects. Its collection includes over 14,000 items, from prehistoric times to periods before, during and after the Khmer Empire, which at its height stretched from Thailand, across present-day Cambodia, to southern Vietnam.

The Tuol Sleng Genocide Museum is a museum in Phnom Penh, chronicling the Cambodian genocide. The site is a former secondary school which was used as Security Prison 21 (S-21) by the Khmer Rouge regime from its rise to power in 1975 to its fall in 1979. From 1976 to 1979, estimated 20,000 people were imprisoned at Tuol Sleng (the real number is unknown). Tuol Sleng was just one of at least 150 torture and execution centers established by the Khmer Rouge, though other sources put the figure at 196 prison centers. It is one of the most popular tourist spots in Phnom Penh.

Choeung Ek is the site of a former orchard and mass graves of victims of the Khmer Rouge - killed between 1975 and 1979. It is the best-known of the sites known as The Killing Fields, where the Khmer Rouge regime executed over one million people between 1975 and 1979. Mass graves containing 8,895 bodies were discovered at Choeung Ek after the fall of the Khmer Rouge regime. Many of the deads were former political prisoners who were kept by the Khmer Rouge in their Tuol Sleng detention center and in other Cambodian detention centers. Today, Choeung Ek is a memorial, marked by a Buddhist stupa. The stupa has acrylic glass sides and is filled with more than 5,000 human skulls. Some of the lower levels are opened during the day so that the skulls can be seen directly. Many have been shattered or smashed. Tourists are encouraged by the Cambodian government to visit Choeung Ek. Apart from the stupa, there are pits from which the bodies were exhumed. Human bones still litter the site.