Before the Thimphu Welcome Gate, Lungtenzampa Bridge was considered the main entrance of Thimphu city. The bridge is traditionally recognized as the ‘Bridge of Prophecy’ in Bhutan. The name of the bridge ‘lungten’ signifying prophecy and ‘zampa’ meaning bridge is of historical importance to Bhutan. The name of this bridge is credited to the story of Lam Phojo Drukgom Zhigpo and Khandum Sonam Peldon.

Phajo Drukgom Zhikpo came to Bhutan in the first half of the 13th century and established the first Drukpa Kagyu sect, which was founded by Drogon Tsangpa Gyarey (Yeshey Dorji) at Ralung, Tibet in 1180. Lama Phajo and Khandum Sonam Peldon were prophesized to meet each other in the Wang Valley (present-day Wang Sisina, Thimphu).

When Lam Phajo arrived in the valley of Wang, he saw a group of girls on the other side of the Wang Chhu (river) and the lama started to sing (lu) to recognize his consort. A young and beautiful girl stood up and answered the lama’s lu. They acknowledged each other, but as there was no bridge over the river they couldn’t meet and went on exchanging their lu alongside the river. Finally, they met each other at a bridge at present-day Lungtenzampa where a large motor bridge has been constructed.

https://dailybhutan.com/article/significance-of-the-stupa-of-two-lovebirds-across-lungtenzampa-the-bridge-of-prophecy