Phrathat Sri Song Rak in Loei Province (fig.), a distinctive stupa in Laotian style, which was built between 1560 and 1563 AD to commemorate the long-lasting friendship between the Siamese King Mahachakraphat of Krung Sri Ayutthaya and the Laotian King Chaiya Chetthathirath of Krung Sri Sattanah Khonhut (Vientiane), ruler of Lan Chang (Lan Xang).

The stupa was regarded as the demarcation of the border between the two kingdoms. Meuang Boraan in features a full-scale replica (fig.).