Muak Lek Arboretum

Muak Lek Arboretum is a 150-acre forest reserve straddling the Saraburi/Nakhon Ratchasima border, 37 km from Saraburi town on Highway 2 — free to enter, open 08:00-16:30 daily, with a stream running through it rather than a single big waterfall.

The gate sits on the left side of Mittraphap Road, directly across from the Dairy Farming Promotion Organization of Thailand’s storefront, easy to spot if you’re driving the Bangkok-Khao Yai route. Inside, trails wind through stands of native hardwoods and flowering understory planted decades ago as a forestry demonstration site. The stream that defines the arboretum starts as tributaries inside Khao Yai National Park, cuts through rock slopes and small rapids as it crosses the grounds, and eventually joins the Pa Sak River, which forms the provincial boundary here. Footbridges cross the water at several points, and low banks make it easy to reach the edge and cool off.

The forest canopy keeps most of the site shaded even at midday, and the water noise is constant background rather than a single dramatic drop — this is a walk-and-wade spot, not a swimming-hole destination. Weekday mornings are quiet; weekends bring day-trippers from Bangkok stopping en route to Khao Yai, since the arboretum sits right on that drive.

Insider Tip: The rock slides and shallow rapids are more fun for kids to wade in than the deeper pools at nearby waterfalls — bring water shoes since the stream bed is uneven.

Watch out: There’s no dedicated swimming area or lifeguard, and rocks near the rapids get slick. Stick to the shallower stretches if you’re wading with children.

Trails can turn muddy after rain, so grip matters more than style in your footwear. For a bigger waterfall stop nearby, Sub Hew Waterfall and Muak Lek Reservoir are both a short drive away in the same district, and the arboretum pairs naturally with a stop at the Dairy Farming Promotion Organization of Thailand right across the road.