NAKHON RATCHASIMA: The new "Thai-US Friendship Trail" at Khao Yai National Park will serve as a model learning centre, said the Department of National Parks, Wildlife and Plant Conservation (DNP).

The trail, which commemorates 200 years of US-Thai diplomatic ties, spans 2.3 kilometres and takes roughly an hour to walk.

Visitors will soon be able to download the department's smartphone app, providing them with useful information at points along the trail via Bluetooth, officials said.

"This trail will serve as an important learning centre for people who are interested in knowing more about the age of the trees inside the park," park chief Kanchit Srinoppawan said at the opening ceremony for the trail on Feb 8.

"All the trees on the trail are relatively young, about 50 years of age. They show how the forest can regenerate itself, unless it is hit by fires or land over-usage," he added.

The new nature trail is in a part of the forest that served as a US Army base during the Laos crisis. 

US troops were stationed in the forested area inside the park from 1959-61. 

Remnants from the former US base can still be found in the park, including some of the footprints of the troops, a helipad that is now used by the Thai air force, and bottle brush trees -- which US troops brought over from Australia.

Khao Yai ranks as the nation's No.1 national park, affording lucky visitors glimpses of Asian elephants, gaurs, Indian muntjacs, Indochinese serows, wild boars and more.