Here’s some Southeast Asian Hindu temples!
Vietnam (before 781)
Main shrine of Prambanan Temple
Indonesia, Java (850)
Cambodia (early 1100s)
Mother Temple of Besakih
Indonesia, Bali (c. 1200s-1500s)
How did Hinduism get to Southeast Asia, you ask? Through sea trade - mostly conducted not by Northern Indians, but by the folks in the South.
Of particular note was the Chola Dynasty (300s BCE–1279 CE), centred in Tamil Nadu, which conquered most of Southeast Asia at one point and forced us to pay tribute. But we didn’t just absorb religion through conquest - there were merchants, like the members of the Ainnurruvar Guild, who sailed the ocean to trade in goods and ideas.
And boy, the influence was huge. Wikipedia notes:
Hinduism in Southeast Asia gave birth to the former Champa civilization in southern parts of Central Vietnam, Funan in Cambodia, the Khmer Empire in Indochina, Langkasuka Kingdom, Gangga Negara and Old Kedah in the Malay Peninsula, the Sriwijayan kingdom on Sumatra, the Singosari kingdom and the Majapahit Empire based in Java, Bali, and parts of the Philippine archipelago. The civilization of India influenced the languages, scripts, calendars, and artistic aspects of these peoples and nations.
The weird thing, of course, is that most of our cultures didn’t stay Hindu. Missionaries came, and we became Buddhist, Muslim, Christian. Even Angkor Wat got transformed from a Hindu temple to a Buddhist one.
Only Bali remains majority Hindu to this day.
Seems to be working out for them.