Angkor
In the early days of Angkor, the worship of Vishnu was secondary to that of Shiva. The relationship seems to have changed with the construction of Angkor Wat by King Suryavarman II as his personal mausoleum at the beginning of the 12th century. The central religious image of Angkor Wat was an image of Vishnu, and an inscription identifies Suryavarman as "Paramavishnuloka," or "he who enters the heavenly world of Vishnu." Religious syncretism, however, remained thoroughgoing in Khmer society: the state religion of Shaivism was not necessarily abrogated by Suryavarman's turn to Vishnu, and the temple may well have housed a royal lingam. Furthermore, the turn to Vaishnavism did not abrogate the royal personality cult of Angkor. by which the reigning king was identified with the deity. According to Angkor scholar Georges Coedès, "Angkor Wat is, if you like, a vaishnavite sanctuary, but the Vishnu venerated there was not the ancient Hindu deity nor even one of the deity's traditional incarnations, but the king Suryavarman II posthumously identified with Vishnu, consubstantial with him, residing in a mausoleum decorated with the graceful figures of apsaras just like Vishnu in his celestial palace." Suryavarman proclaimed his identity with Vishnu, just as his predecessors had claimed consubstantiation with Shiva.
Phnom Bok
Yasovarman I, son of Indravarman I (his capital was at Hariharalaya), shifted the capital to Yashodarapura (the first Angkor capital meaning "The City That Bears Glory"). The temples that he built, apart from Phnom Bok in 910 AD consisted of the Lolei (893 AD), Pra Vihear (893 AD), Phnom Bakheng, the Royal temple (900 AD) and Phnom Krom (910 AD). However, Yashovarman did not choose Phnom Bok as the capital city, near the city of Hariharalaya, as he considered it unsuitable due to its "awkward and too high" a location to mark as the centre of the city. He did not choose Phnom Krom hill either, as he considered it too close to the Tonle Sap Lake. Eventually, Phnom Bakhen of the triumvirate of hills was chosen as the capital city due its low height and large expanse of land available to establish a capital city. His objective was also to build a temple for housing a linga, which surpassed his father's Indresvara and named it as Yashodaresvara. He also named his capital as Yashodarapura, which became the first capital city of Angkor. He, however, installed the Trimurtis in the temples on the other two hills of Phnom Bok and Phnom Krom.
Statues of the Hindu Trimurti were found at both Phnom Bok and Phnom Krom.