Destination guide

Mat Than Mountain

A limestone peak pierced by a round hole more than 50 m across, mirrored in a lake in the rainy season.

50 mwidth of the “eye”

650 – 700 melevation of the tower karst

15 haNam Tra lake in the rainy season

30 kmfrom the provincial centre

Mat Than Mountain – Phia Piot, “pierced mountain”, in Tay – is in former Cao Chuong commune, in the Tra Linh – Trung Khanh area. It is one of the Geopark’s geosites: a round tunnel through the summit, more than 50 m across, about 50 m above the lake below.

Around it lies tower karst at about 650 – 700 m. In the rainy season Nam Tra lake, about 15 ha, mirrors the peaks; from September the water drains away and the lake bed becomes meadow where villagers graze buffalo, cattle and horses. Young Vietnamese travellers also call it “Tuyet Tinh Coc”.

Don’t miss

The mountain’s “eye”

A limestone trail climbs right up to the hole, with a view straight through the mountain and across the valley. Go with a local.

Nam Tra lake

Full of water around June – August, reflecting the peaks; a green meadow in the dry season.

Nam Tra waterfall

About 500 – 600 m from the lake, roughly a 10-minute walk.

Ban Danh Tay hamlet

About 15 minutes on foot, with yin-yang tiled stilt houses and hand-built stone walls.

Getting there

About 30 km from the provincial centre towards Tra Linh.
It sits on the eastern loop, so it fits easily into a Ban Gioc – Phong Nam trip, often as an afternoon stop on the way back to the provincial centre.

See the place card and directions →

When to go

Jun – Aug

Nam Tra lake is full and the peaks are mirrored in it.

Sep – Nov

Clear skies, green meadows and easier climbing; loveliest in late afternoon.

Dry season

Good for camping below the mountain and stargazing.

Practical tips

Before you go

The trail to the eye is steep, with sharp rock that is slippery when wet: climb only in dry weather, with grippy shoes and a local guide.
Camp only where allowed, take your rubbish home and never light fires near the forest.
The meadow is grazing land: walk quietly, don’t chase livestock and close any gate you open.