Siam Tulip Fields, Pa Hin Ngam National Park

Its story began in 1985, when a survey found the Pa Hin Ngam area beautiful and suited to recreation, and a proposal went via Chaiyaphum province to the Royal Forest Department. Thai Wikipedia says it became Pa Hin Ngam Forest Park that same year, while English Wikipedia says a forest park of about 10 km² was created in October 1986. A later, more detailed survey added the forest along the Phang Hoei ridge, the headwaters of the Lam Khan Chu, which flows into the Chi River.

English Wikipedia continues that the Forest Department surveyed thoroughly in 1993 and recommended national-park status; a national park of about 100 km² was created on 19 September 1994 and formally gazetted on 6 June 2007, the date Thai Wikipedia takes as its founding.

The name "Pa Hin Ngam" (forest of beautiful rocks) comes from Lan Hin Ngam, a sandstone area of over 10 rai west of the park office, shaped over a long time by water and wind into odd forms named after what they resemble, such as a hen, nails, a radar, Hin Mo Ham Tang and a rock called Phra Siwali. Thai Post says Lan Hin Ngam is also a registered dark-sky area for stargazing.

Stargazing tourism around Pa Hin Ngam keeps growing. Dailynews reported in July 2025 that the Tourism Authority of Thailand and the National Astronomical Research Institute (NARIT) registered 16 new dark-sky areas, including Phu Phrom Dao Farmstay, over 40 rai at 600–870 m and surrounded by Pa Hin Ngam National Park forest.

Sut Phaendin, about 2 km from the office at about 846 m, is the highest point of the Phang Hoei range, looking down on the Sonthi River valley and Sap Langka Wildlife Sanctuary. "Sut Phaendin" ("end of the land") refers to where the edge of the Khorat Plateau drops toward the Central Plains. Pha Ham Hot viewpoint lies on the same ridge.

The krachiao here is Curcuma alismatifolia of the ginger family, which Thai Wikipedia calls pathumma. It sprouts from underground rhizomes and blooms early in the rainy season, about June to August. The park has three fields, seen along about 1 km of raised walkway, since visitors may not step directly into the fields, though field 1 has a photo area. Thai Post says the flowers come in pinkish-purple, white and green.

The flower Thais call krachiao or pathumma is native to Laos, northern Thailand and Cambodia. English Wikipedia notes it is known abroad as the Siam tulip, though it is not a tulip but a close relative of turmeric; other Thai names include krachiao bua and khamin khok, and it received an IUCN Red List assessment in 2019. Department of Agriculture data says it is an export crop: in 2013–2017 about 75% of bulbs were exported, worth about 15–30 million baht for bulbs and 40–70 million baht for flowers, from about 400 rai of farms including in Chaiyaphum.

Chaiyaphum holds the Dok Krachiao Festival every year. Thai Post reports that in 2023 it ran from 1 July to 31 August, opening at Pa Hin Ngam National Park with a flower-float parade, cycling through the fields, a fancy-dress run and stargazing, and a performance by the Nyah Kur ethnic community. Nearby Sai Thong National Park also has krachiao fields on the Phang Hoei range.

The krachiao festival has run for many years. MGR Online reported on 10 June 2008 that the Chaiyaphum Provincial Administrative Organization and the province opened the "Beautiful Krachiao Festival" at Pa Hin Ngam National Park, with about 5,000 people on opening day, 300,000–500,000 visitors expected over June–August, and 50–100 million baht in spending; activities included building check dams, replanting krachiao and showcasing Nyah Kur life. Matichon reported in June 2017 that governor Chusak Trisan opened the festival before tens of thousands of visitors, with over 100 rai of fields at Pa Hin Ngam and at Sai Thong National Park in Nong Bua Rawe.

The Phang Hoei forests are also home to the Nyah Kur, once called "Chao Bon" by officials. Matichon says Ban Rai, a Nyah Kur village, is about 8 km from the park entrance. Asst. Prof. Phiphat Krachaechan writes in Silpa Watthanatham that Nyah Kur is a Monic (Mon–Khmer) language; linguist Gérard Diffloth (1984) found it very close to Dvaravati-era Mon, splitting off around the 11th century. Thida Saraya (1989) suggested some Dvaravati people retreated to the hills and became the Nyah Kur, though the author finds no firm evidence of a Dvaravati link. Nyah Kur legends tell of losing a castle to the Khmer and moving into the mountains, and archaeological sites lie near Chong Chit, an old pass linking the Central Plains and Isan. A GotoKnow article adds that Nyah Kur communities also live in Nakhon Ratchasima and Phetchabun, and that the language is declining as it has no script and most speakers are elderly.

The park also has a three-tiered waterfall on the Huai Krachon, which English Wikipedia calls Namtok Thep Phana, flowing only in the rainy season. The forest is mostly dry dipterocarp with patches of dry evergreen forest.

The park is managed by the Department of National Parks, Wildlife and Plant Conservation. Wikipedia records 106,428 visitors in 2019, most of them during the krachiao season.